Irrigation
Plant-based sensors that measure the thickness and electrical capacitance of leaves show great promise for telling farmers when to activate their irrigation systems, preventing both water waste and parched plants, according to researchers in Penn State's College of Agricultural Sciences.

Continuously monitoring plant "water stress" is particularly critical in arid regions and traditionally has been done by measuring soil moisture content or developing evapotranspiration models that calculate the sum of ground surface evaporation and plant transpiration. But potential exists to increase water-use efficiency with new technology that more accurately detects when plants need to be watered.
For this study, recently published in Transactions of the American Society of Agricultural and Biological Engineers, lead researcher Amin Afzal, a doctoral degree candidate in plant science, integrated into a leaf sensor the capability to simultaneously measure leaf thickness and leaf electrical capacitance, which has never been done before.

The work was done on a tomato plant in a growth chamber with a constant temperature and 12-hour on/off photoperiod for 11 days. The growth medium was a peat potting mixture, with water content measured by a soil-moisture sensor. The soil water content was maintained at a relatively high level for the first three days and allowed to dehydrate thereafter, over a period of eight days.

The researchers randomly chose six leaves that were exposed directly to light sources and mounted leaf sensors on them, avoiding the main veins and the edges. They recorded measurements at five-minute intervals.

The daily leaf-thickness variations were minor, with no significant day-to-day changes when soil moisture contents ranged from high to wilting point. Leaf-thickness changes were, however, more noticeable at soil-moisture levels below the wilting point, until leaf thickness stabilized during the final two days of the experiment, when moisture content reached 5 percent.

The electrical capacitance, which shows the ability of a leaf to store a charge, stayed roughly constant at a minimum value during dark periods and increased rapidly during light periods, implying that electrical capacitance was a reflection of photosynthetic activity. The daily electrical-capacitance variations decreased when soil moisture was below the wilting point and completely ceased below the soil volumetric water content of 11 percent, suggesting that the effect of water stress on electrical capacitance was observed through its impact on photosynthesis.

"Leaf thickness is like a balloon—it swells by hydration and shrinks by water stress, or dehydration," Afzal said. "The mechanism behind the relationship between leaf electrical capacitance and water status is complex. Simply put, the leaf electrical capacitance changes in response to variation in plant water status and ambient light. So, the analysis of leaf thickness and capacitance variations indicate plant water status—well-watered versus stressed."

The study is the latest in a line of research Afzal hopes will end in the development of a system in which leaf clip sensors will send precise information about plant moisture to a central unit in a field, which then communicates in real time with an irrigation system to water the crop. He envisions an arrangement in which the sensors, central unit and irrigation system all will communicate without wires, and the sensors can be powered wirelessly with batteries or solar cells.

"Ultimately, all of the details can be managed by a smart phone app," said Afzal, who studied electronics and computer programming at Isfahan University of Technology in Iran, where he earned a bachelor's degree in agricultural machinery engineering. He is testing his working concept in the field at Penn State.

Two years ago, he led a team that won first place in the College of Agricultural Sciences' Ag Springboard contest, an entrepreneurial business-plan competition, and was awarded $7,500 to help develop the concept.

Growing up in Iran, Afzal knows water availability determines the fate of agriculture. In the last decade, the Zayandeh River in his home city of Isfahani has dried up, and many farmers no longer can plant their usual crops. "Water is a big issue in our country," said Afzal. "That is a big motivation for my research."

Afzal's technology is very promising, noted Sjoerd Duiker, associate professor of soil management, Afzal's adviser and a member of the research team. Current methods to determine irrigation are crude, while Afzal's sensors work directly with the plant tissue.

"I believe these sensors could improve water-use efficiency considerably," Duiker added. "Water scarcity is already a huge geopolitical issue, with agriculture responsible for about 70 percent of world freshwater use. Improvements in water use efficiency will be essential."

In a follow-up study, Afzal has just finished evaluating leaf sensors on tomato plants in a greenhouse. The results confirmed the outcomes of the just-published study. In his new research, he is developing an algorithm to translate the leaf thickness and capacitance variations to meaningful information about plant water status.
If you leave your pivot exposed all through the winter, you’re going to be working on it a lot longer in the spring,” says Jeff Ewen, an irrigation agrologist with the Saskatchewan Ministry of Agriculture in Outlook, Sask. To help producers prevent damage from winter’s storms and bone-chilling temperatures, Ewen offers a number of winterizing tips.

Apr. 21, 2016 - Deciding on the correct water application solution is vital to your center pivot's performance. Here are three questions you need to ask yourself before picking out a sprinkler package with your dealer.

1. What is your soil type and texture? Proper sprinkler design and selection helps reduce soil sealing with medium to heavy soils.
2. What crops are you growing? A significant challenge with sprinkler head design is its ability to penetrate the crop canopy.
3. What does your field's terrain look like? The slope of your field must be considered when choosing sprinklers to minimize runoff and ​to keep water where it does your crop the most good.

By using your answers to these questions, you will be prepared to work with your dealership's water application experts to help determine how best to reduce energy cost, save water on your farm, and maximize your profitability.

For more information on sprinkler packages and water application solutions, get your free eBook 8 Tips to Accurately Check Your Center Pivot Sprinklers.

 

 

 

Every 15 minutes, 685 kilometres out in space, the National Aeronautics and Space Administration (NASA) satellite known as SMAP (Soil Moisture Active Passive) records the earth’s soil moisture and temperature. NASA then uses that data to produce the most accurate maps of global soil moisture, temperature and freeze-thaw states ever created with data from space. Agriculture and Agri-Food Canada (AAFC), Environment Canada and university scientists are assisting NASA in validating SMAP soil maps. AAFC is also producing higher resolution soil moisture maps from the Canadian RADARSAT-2 satellite.

The maps from SMAP and RADARSAT-2 are valuable tools that help improve people’s understanding of the processes affecting weather and climate. This, in turn, can help agricultural production.

“Soil moisture is an important variable in the development of extreme events,” says Heather McNairn, the AAFC team lead and a research scientist for geomatics and remote sensing in Ottawa. “If we don’t have enough water in the soil, drought can develop; if we have extended periods of wet soils, it puts us at risk of flooding.”

This is where the information from SMAP and RADARSAT-2 comes in. It reveals how much moisture is in the soil so scientists – and producers – can understand the risks for drought or flooding.

“Knowing how much water is available in the soil can help us understand drought risk, where drought might be developing and how severe the drought might be,” McNairn says. “If we can measure how much water is in the soil, we can determine if the soils have enough reserve space to absorb spring snow melt and rainfall. If the soils are saturated, they are unable to accommodate additional water and this tells us the risk of flooding is high.”

From an agricultural perspective, monitoring soil moisture will enable the sector to better mitigate agricultural risks regionally and nationally. It will also help Canadian producers make informed decisions for their farm operations based on changing weather, water and climate conditions. For example, producers could use the data to determine their variable rate irrigation needs.

Environment Canada will use data from SMAP for improved weather forecasting since the amount of water in the soil significantly affects temperature and rainfall forecasts. “We don’t currently have good data on soil moisture across Canada,” McNairn says.

The data will also help researchers outside of Canada, such as in Chile where agronomists are looking at variable rate irrigation. “Producers don’t know how to variably apply water because they don’t know where the moisture is in their fields,” McNairn says. She is assisting researchers in Chile to integrate soil moisture maps from SMAP and RADARSAT-2 into their variable rate irrigation practices.

While NASA launched SMAP in January 2015, AAFC began working with the space agency three years earlier. That’s when an AAFC team from Ottawa and Winnipeg took part in SMAPVEX12, a six-week field-testing campaign that involved government and university scientists collecting soil and plant measurements in southern Manitoba while NASA flew two aircraft equipped with the same sensors as the SMAP satellite. The measurements from that mission were then used to calibrate and validate the processing models NASA was planning to use with SMAP.

During the SMAP mission, which is expected to run at least three years, AAFC will provide NASA with data from its network of 12 soil monitoring stations in Manitoba and five in Ontario, all installed at private farm sites. The SMAP team will use this data to assess the accuracy of SMAP’s soil moisture products.

The 2012 SMAPVEX experiment used data from NASA aircraft to simulate what soil moisture maps from SMAP would look like. Now that SMAP is launched, NASA is returning to Manitoba this year for a second experiment. SMAPVEX16 will validate actual data from the satellite, and NASA will use what is learned during SMAPVEX16 to improve its models and SMAP’s global soil moisture maps.

Canada also collects data from its own satellite, RADARSAT-2, to produce soil moisture maps at resolutions higher than those produced by SMAP. These methods will be carried forward and used with Canada’s next generation of satellites, the RADARSAT-Constella­tion scheduled to launch in 2018. With this Constellation, data for use in soil moisture mapping would be available from three satellites.

“SMAP and RADARSAT-2 can work together to provide a range of soil moisture products,” McNairn says. The SMAP sensor provides very coarse resolution images covering approximately 1,000 kilometres, which are very good for large scale forecasting of weather and floods, but not detailed enough for field scale mapping. This is where higher resolution data from RADARSAT-2 can help.

Scientists are validating the maps from SMAP and also tackling how to downscale SMAP data to improve the resolution of soil moisture maps from this NASA satellite. Downscaled SMAP soil moisture products would provide producers with better data for use in variable rate irrigation and determining the disease risk at the field level. For example, “the risk of some crop diseases increases if the soil is wet for many days,” she explains. “The temporal persistence of wetness tells about risks and if we can determine this risk, this information will help producers make decisions in managing this risk.”

For now, it’s exciting that NASA is providing soil moisture maps for the whole world every three days, McNairn says. “We couldn’t do that without satellites.”

 

Mar. 21, 2016 - Alberta Agriculture and Forestry (AF) undertakes a number of research projects to ensure the quality and safety of land, air, and water for our food producers. Although long-term monitoring shows the overall quality of Alberta's irrigation water is good or excellent, a study is currently underway to use DNA fingerprinting techniques to determine the sources of contamination of irrigation water. While there are no current concerns, this is an opportunity to improve water quality for the future.

The Water Quality Section of AF is currently working with the Taber Irrigation District on a pilot study to understand the sources of E. coli in irrigation water. The study is funded by Growing Forward 2, a federal-provincial-territorial initiative. The District has made water quality a key part of their mandate to ensure farmers are growing the best quality crops.

Often, irrigators are required to have water quality tests completed to market their produce, and with recent changes in regulations in the United States (US), this need may increase. In the US, the Food Safety Modernization Act requires testing of water that is used to irrigate fruits and vegetables which are consumed raw. These regulations may affect Alberta producers with irrigated crops destined for export to the US.

This study will assist in identifying opportunities to continue to improve water quality, and help producers meet their food safety requirements for the global marketplace. The key item being measured in the study is E. coli. Generic E. coli are present in the intestines of most people and animals, and are excreted in feces. E. coli are therefore used to measure fecal contamination in water. The testing is complicated, as there are "naturalized" E. coli that occur in the environment and are not indicative of fecal contamination.

"Research gives us a better understanding on the amount of fecal and naturalized E. coli in irrigation water. The discovery of naturalized E. coli is very important because food safety is concerned about fecal contamination. If we find E. coli in water, we need to determine whether it is fecal or naturalized, which then determines if there is a food safety concern or not," says Andrea Kalischuk, director of water quality, AF.

"Our study in the Milk River area showed cliff swallows and cattle contaminated some of the water, but a significant proportion of naturalized E. coli was also observed" says Kalischuk. Whatever the study identifies as a source of contamination, the research team and irrigation district will need to work with producers to seek a balanced solution that supports both the agriculture industry and wildlife habitat, while meeting food safety requirements.

This is the final year of a three-year study, and a summary report will be shared with producers on AF's website in the fall of 2017.

 

Mar. 15, 2016 - Grasslands in North America could well be more productive in future climate scenarios, a new research study shows.

Researchers from the United States and Canada, including University of Lethbridge biologist Dr. Larry Flanagan, used a new modelling method to predict how native grasslands could respond to climate change and their results are pointing to increased productivity, even under slightly drier environmental conditions.

"Overall, our projections indicate significant gains in grassland cover by 2100 across major areas of western North America that are dominated by grasslands at present," says Flanagan. "This was particularly true in the northern grassland regions that are often limited by cool temperatures in the early growing season. Warmer temperatures can cause an earlier start to the growing season, by as much as a few weeks."

Grassland growth occurs quickly and depends on precipitation and soil water content. To predict daily changes in grassland cover, the researchers developed a model that calculated plant growth and the soil water budget, and calibrated it using measurements made at a range of field sites. Once the model was successfully tested, it was run under a new set of environmental conditions that consisted of climate projections for the next century. These projections were provided by Coupled Model Intercomparison Project Phase 5 (CMIP5), a five-year climate change modelling research strategy that is co-ordinated by the World Climate Research Program.

"Our analysis indicates a likely future shift of vegetation growth towards both earlier spring emergence and delayed autumn senescence, which would compensate for drought-induced reductions in summer growth and productivity associated with climate change," says Flanagan.

The model doesn't include the effects of rising levels of atmospheric carbon dioxide on photosynthesis and water use efficiency, factors that could magnify the positive impact of climate change on the grasslands.

Grasslands cover more than 30 per cent of the world's land surface and are fundamental to the meat and dairy industries. This projected increase in productivity of grasslands has implications for agriculture, carbon cycling and vegetation feedbacks into the atmosphere.

"The stimulation of grassland plant growth by warmer temperatures is strongly dependent on adequate soil moisture being present in new climate change scenarios. The positive trends in native grassland cover we currently predict for the next 100 years could be stalled by lack of moisture or other environmental limitations. So climate change could also have significant additional demands on irrigation and nutrient management that influence agricultural productivity in the next century," cautions Flanagan.

The research study by Flanagan and his colleagues can be found on the Nature Climate Change website under the 'Latest research' tab.

Mar. 8, 2016 - With flooding across the province in recent years, there is a lot of discussion at provincial, municipal and federal levels on how to manage the flow of water to minimize the destruction of land and infrastructure during high water events.

As a landowner, there's a role you can play in this plan as well, especially with the help of the Manitoba Habitat Heritage Corporation (MHHC).

The Corporation is in the middle of a significant wetland restoration project and they are looking for landowners to help them meet the project objectives.

There are a number of advantages to restoring wetlands, but the main benefit that landowners are often most interested in is the actual retention of water. Deloraine landowner, Gord Weidenhamer, recently added a 10-year wetland restoration agreement to enhance a wetland already under an existing conservation agreement with MHHC.

"Nature took a lifetime to create it and to try to get it back takes a lot of steps and a lot of work. These conservation projects help to restore the natural lands and I think people should take advantage of them and really look at the big picture. The land was drained by previous owners, but it didn't provide any benefit as far as the grazing goes, the wetlands were still there especially during high water years," said Weidenhamer.

The 32 acre wetland restoration on Gord Weidenhamer's and Glen Scott's properties is just one example of the many projects, big and small, that have been funded through MHHC with support from Environment and Climate Change Canada and its Lake Winnipeg Basin Stewardship Fund.

Research and land surveys are always completed in cooperation with the landowners to determine what the water level should be at and to provide direction on the best means of restoring the natural landscape.

Since Weidenhamer's land is in the headwaters, he's hoping the reclamation of this wetland will help to alleviate some problems downstream.

"If every municipality could look at these programs and utilize them, I think there would be real benefits to storing some water and slowing down water that's heading downstream," said Weidenhamer.

The Manitoba Habitat Heritage Corporation is a non-profit, Crown corporation with a mandate to conserve, restore and enhance fish and wildlife habitat in Manitoba through conservation initiatives that promote healthy ecosystems and biodiversity.

If you're interested in participating in the Wetland Restoration project, contact Tom Moran (204-305-0276) or Scott Beaton (204-471-9663).

 

Dense, compacted subsoil layers can have serious crop yield impacts. They can impair root penetration, limiting root access to water and nutrients, and they can decrease water infiltration and increase the risk of ponding, runoff and erosion. One way to try to improve soil with a compacted layer is to use a deep tillage implement, but that can be expensive. So University of Saskatchewan (U of S) soil scientist Jeff Schoenau is leading a new project to evaluate precision subsoiling.

A common cause of subsoil compaction is repeated wheel traffic, for example in travel and loading areas, especially if heavy field equipment is used on clayey soils in wet conditions. As well, natural soil-forming processes can create a hardpan layer, such as in Solonetzic soils.

Solonetzic soils have a hard, sodium-rich B horizon (the soil layer below the topsoil, or A horizon). “The presence of large amounts of sodium causes some soil dispersion and the creation of these hardpans due to clay movement into the B horizon,” Schoenau explains.

The majority of Canada’s six to eight million hectares of Solonetzic soils are found in Alberta and Saskatchewan. Solonetzic soils tend to occur in areas with high-sodium parent materials or where groundwater carries sodium into the soil. For example, there are broad areas dominated by Solonetzic soils along the edge of the Missouri Coteau in Saskatchewan, such as the Central Butte area and the Radville to Estevan area.

Building on previous findings
Although subsoiling was studied in past decades on the Prairies, not much research had been done recently until Schoenau’s research group conducted a study that began in 2010. In that study, they used a paraplow, a type of subsoiler that has been on the market for quite a while. As the tip of a paraplow moves through the subsoil, it lifts and then drops the soil column, loosening the soil. It causes limited disturbance of the soil surface, as the loosening point is run at a depth of 45 centimetres.

That study’s treatments compared spring and fall subsoiling, two different subsoiling depths and two different shank spacings. It took place at three irrigated sites and one dryland site in south-central Saskatchewan in the Lake Diefenbaker area.

One site had soil structural issues because of its Solonetzic soils. Unfortunately, the study’s fieldwork took place during two unusually wet years, 2010 and 2011, and the Solonetzic site had to be abandoned due to flooding.

At the other sites, the researchers didn’t detect any serious compaction problems. Nevertheless, subsoiling did affect soil conditions and water infiltration at those sites.

“One of the things we found is that subsoiling did significantly increase the infiltration of water and reduced the density and strength of the soil. How long those effects persist depends on the moisture conditions; we tended to see less persistence if it was really wet than if it was dry,” Schoenau says.

Subsoiling resulted in variable and typically small yield increases of about five to eight per cent. He notes, “If you compare that yield advantage to the subsoiling costs, it was about a breakeven proposition. We concluded that the effects would have to persist longer than one year or else be of a larger magnitude in order for subsoiling to be really economical on these particular soils, where serious compaction issues were not evident.”

Current project
So, if you break even on subsoiling costs in soils without serious compaction problems, then might subsoiling be economical if it were just targeted at those patches in a field where serious soil structural problems occur?

Schoenau’s new precision subsoiling project could help answer that question.

He is working on this project with his colleague in the department of soil science, soil physicist Bing Si. The Saskatchewan Agriculture Development Fund, Saskatchewan Wheat Development Commission and Western Grains Research Foundation are funding the project.

The two sites for this project are both in the Lake Diefenbaker area near Central Butte and are both dryland locations. At one site, the researchers have induced some soil compaction through repeated wheel traffic. At the other site, they have set up a smaller experiment on a field with significant structural limitations due to a Solonetzic hardpan layer.

In the fall of 2015 at the two sites, the researchers began by mapping the location and depth of spots where the subsoil’s soil strength and density were high enough to limit root growth. “We have a cone penetrometer, and we use a sampling grid to make maps of the penetration resistance [soil strength] before and after the subsoiling,” explains Schoenau. A cone penetrometer is an instrument consisting of a narrow steel shaft with a cone at one end. As the penetrometer is pushed into the soil, the pressure gauge at the top end of the shaft indicates how much pressure is needed to move the cone through the soil.

Also in the fall, the researchers carried out the subsoiling in replicated plots, comparing three treatments: subsoiling only those parts of the plot identified as having a dense subsoil layer; subsoiling the entire plot; and no subsoiling, as a check.

They used a modern subsoiling implement – a John Deere 2100 minimum till ripper provided by Western Sales, a Saskatchewan farm equipment dealer. These types of subsoilers have a set of coulter disks to open the soil and then a following set of shanks with a near-horizontal tip (or share) at the base of each shank. Schoenau says, “As the unit moves through the soil there is little disturbance at the soil surface, just from the shank itself. But down deep at the depth of operation, which is around 30 centimetres, the shank creates a lifting or loosening action.”  

He explains that dense subsoil layers typically occur at variable depths below the surface. He adds, “In some of our early work, we found that if we went too shallow, subsoiling didn’t work as well. Similarly if we widened the spacings above what was recommended and went to really wide spacings, we didn’t get as good results.”

For the next two years, the researchers will be monitoring the effects of the 2015 subsoiling on soil properties and crop yields. Schoenau says, “In the spring of 2016, we will be looking at the persistence of the effects on bulk density and penetration resistance. Then we’ll measure crop yield at the different transect points in our replicated plots. And we’ll be doing that for the following two years so we will have yield data from wheat in 2016 and canola in 2017.” Then they’ll evaluate the costs and benefits of precision subsoiling compared to subsoiling of a whole field.

For crop growers with fields that have zones of high-density subsoils, the project should provide new information on the value of precision subsoiling.

“I think it will show the potential benefits of applying the subsoiling technique to soils and particularly to areas of a field where there is an issue with soil compaction from wheel traffic under very wet conditions or naturally occurring dense B horizons,” Schoenau says.

“I think it will give us insight into how subsoiling affects the properties of the soil and ultimately how that translates into any potential yield benefits and enhanced economic returns to the grower.”

 

Jan. 4, 2016 - A recent study of plant genetics indicates that alfalfa, a forage crop used primarily for livestock, could be made more drought-resistant, which would reduce costs for producers and benefit the environment.

Agriculture and Agri-Food Canada (AAFC) research scientist Dr. Abdelali Hannoufa, who specializes in functional genomics and metabolic engineering, has discovered a gene in the alfalfa plant that regulates its capacity to maintain water content.

"The gene reduces water loss, so that the plant maintains its water content and can resist drought for a longer period of time," he says.

The gene in question is called microRNA156.

Hannoufa studies crop genetics at AAFC's London Research and Development Centre in Ontario. Collaborating with industry partners, he is finding ways to improve alfalfa through genomics.

"The gene (microRNA156) reduces water loss, so that the plant maintains its water content and can resist drought for a longer period of time," says Hannoufa.

MicroRNA156 "is a master gene regulator," he adds. "It functions by regulating a network of other genes, called down-stream genes, which control yield, stress tolerance and other factors."

The gene's function is being studied closely and the findings are applied to plants grown under controlled conditions in the Centre's state-of-the-art greenhouse facility.

Industry partners are also adapting this technology for use in field trials.

Results show that the gene also increases alfalfa's root length. Longer roots allow the plant to reach deeper into the soil to absorb water and can lock in nutrients, such as nitrogen. Enhanced nitrogen fixation can reduce the need for subsequent fertilizer applications.

Drought resistance is an important trait because it maintains a crop's viability through unpredictable climate conditions and increases its adaptability to grow in various soil types. Combined, these benefits translate into savings for the producer.

Alfalfa is also cost-efficient because it is a perennial crop. "You don't have to seed it every year," he notes.

In addition to being a valuable forage crop, "alfalfa is also being looked at as a crop for land reclamation," he says. Alfalfa's adaptability to less-than-ideal growing conditions means it can help restore soil that has been degraded through prolonged use, or at sites of oil and gas explorations.

Seeded over approximately five million hectares across Canada, Hannoufa says alfalfa is one of Canada's most important crops, but its full potential has yet to be realized because "it is being contemplated as a competitive, low-input bioenergy crop."

Ongoing research of gene functions, including that of other major crops like canola, may lead to further discoveries that enhance crop quality and performance under less-than-ideal production conditions.

Sept. 1, 2015 - Today, Minister responsible for the Water Security Agency Herb Cox announced new drainage regulations in Saskatchewan. The new regulations are the first phase of an agricultural water management strategy that recognizes the benefits of drainage and the importance of mitigating negative impacts.

"We recognize drainage is an important water management tool for producers and these new regulations will help us streamline the approval process to help producers become compliant while mitigating damage downstream," Cox said. "These new regulations are part of the development of a risk based agricultural water management strategy that will improve the overall process, including applications and investigating complaints, and will help prevent future issues."

The key changes in the new regulations are:

  • ensuring that impacts related to flooding, water quality and habitat loss are addressed as part of the drainage works approval process;
  • allowing landowner agreements as evidence of land control;
  • simplifying and streamlining the application approval process;
  • no longer exempting works constructed before 1981 from requiring an approval; and
  • enabling the use of "qualified persons" in the design of higher risk drainage works.

These drainage regulations fulfill a commitment made in the 2014 Speech from the Throne. This is the first significant change to drainage regulations in 35 years.

The new drainage regulations were created after extensive online and industry stakeholder consultations. More than 500 public participants and 15 industry and environmental groups provided input into the creation of the new approach to drainage in Saskatchewan.

The new regulations are the first step in a phased-in approach to bring all drainage in the province into compliance over the next 10 years. These changes facilitate the start of the overall approach to the agricultural water management strategy.

The next phase of the agricultural water management strategy will be the development and refining of policies and program delivery which will be used in a series of pilot projects and then expanded to the rest of the province.

The pilot projects are based in the Souris Basin near Stoughton and the Assiniboine Basin near Canora. Local producers, watershed authorities and representatives in those areas have committed to working with the WSA to implement the new agricultural water management strategy and to help bring existing drainage projects into compliance.

The WSA will continue working with stakeholders on this strategy to develop policies on mitigation, application processes and informational materials.

"Drainage is one of the major issues facing rural Saskatchewan so we are pleased that the government is implementing regulations meant to address deficiencies with the current system," Saskatchewan Association of Rural Municipalities President Ray Orb said. "We have been awaiting this announcement and look forward to working with the government on the implementation of these regulations and further refinement of the agriculture water management strategy as it is phased in over the next few years."

 

July 27, 2015 - Manitoba Infrastructure and Transportation's Hydrologic Forecast Centre advises that significant rainfall is forecast for parts of southwestern Manitoba and Saskatchewan in the next three to four days. As much as 100 millimetres of rain could fall, starting later today.

Various weather forecasts indicate variable amounts and different areas where the precipitation will fall. If the maximum forecasted rainfall amount occurs, it could generate potential overland flooding and raise river levels across much of southwestern Manitoba.

The Shellmouth Dam is currently at the summer target level and the Qu'Appelle River has a slightly higher than normal flow for this time of the year. However, soils are generally much drier than 2014 when a similar heavy rain event led to issues with flooding, so it is anticipated the effects will not be as serious.

Flash or overland flooding could happen in areas hit by heavier rainstorms. Communities in southwestern Manitoba are advised to take necessary precautions. Detailed impacts on tributaries and main stem rivers will be evaluated as a clearer picture of this active weather emerges.

Rainfall amounts will be variable depending on stronger thunderstorms which will be embedded in the larger area of rain. Current indications are for the heaviest band of rain to extend through the southern and southeastern Saskatchewan area with local amounts of 100 mm or more.

Flooding can affect road conditions quickly. Before travelling, check road conditions by calling 511. Listen to radio or TV weather and flood updates. Do not walk through moving water, even as little as six inches (15 cm).

Do not drive into flooded areas. If floodwaters rise around your car, abandon the car and move to higher ground if you can do so safely. Do not touch electrical equipment if you are wet or standing in water.

 

By Rup Chakravorty

In the United States, federal mandates to produce more renewable fuels, especially biofuels, have led to a growing debate: Should fuel or food grow on arable land? Recent research shows farmers can successfully, and sustainably, grow both.

Russ Gesch, a plant physiologist with the USDA Soil Conservation Research Lab in Morris, Minnesota, found encouraging results when growing Camelina sativa with soybean in the Midwest.

Camelina is a member of the mustard family and an emerging biofuel crop. It is well suited as a cover crop in the Midwest. "Finding any annual crop that will survive the [Midwest] winters is pretty difficult," says Gesch, "but winter camelina does that and it has a short enough growing season to allow farmers to grow a second crop after it during the summer."

Additionally, in the upper Midwest, soils need to retain enough rainwater for multiple crops in one growing season. Gesch and his colleagues measured water use of two systems of dual-cropping using camelina and soybean. They compared it with a more typical soybean field at the Swan Lake Research Farm near Morris.

First, researchers planted camelina at the end of September. From there growing methods differed. In double-cropping, soybean enters the field after the camelina harvest in June or July. Relay-cropping, however, overlaps the crops' time. Soybeans grow between rows of camelina in April or May before the camelina plants mature and flower.

The benefits were numerous. Relay-cropping actually used less water than double-cropping the two plants. Camelina plants have shallow roots and a short growing season, which means they don't use much water. "Other cover crops, like rye, use a lot more water than does camelina," says Gesch.

Conveniently, the extra water use during dual-cropping takes place in the spring. "We tend to have an excess of moisture in the soil in the spring from the melting snow pack," says Gesch. Growing camelina as a winter cover crop can help farmers take advantage of spring's extra moisture.

Gesch points out the need for more water use does mean camelina dual-cropping may not be the best option in all areas. "As you get further west and precipitation drops off and soils get lighter with lower water-holding capacity, crop yields may start to go down," says Gesch.

Growing camelina as a winter cover crop can also have other benefits, according to Gesch. "We had greater soybean yields with the relay-cropping system than when double cropping," says Gesch, referencing a previous study. The earlier planting date during relay cropping allows for a longer growing season and contributes to the higher yield, according to Gesch.

In addition, camelina plants flower early in the spring, providing a vital food source for pollinators, like bees, when little else is available to them. As a cover crop, camelina may also help prevent erosion and build soil carbon content. Gesch and his colleagues are working to measure these ecological benefits of dual-cropping.

"We wanted to find alternative crops that could be integrated into the Midwestern corn/soybean cropping system in a sustainable way that also makes economic sense for farmers," says Gesch.

In camelina, they may have found just such a plant. Gesch's study was recently published in Agronomy Journal.

 

May 19, 2015 - Cold temperatures, combined with excessive rainfall in some areas and even snowfall, has created conditions not ideal for the germination and emergence of corn planted recently in Manitoba. Research has shown that temperatures at or below 10 C are most damaging to the germination and emergence process, especially if the cold temperatures persist long after planting.

What is Imbibitional Chilling Injury? Firstly, imbibition is the process by which seeds absorb water for the initiation of germination. In corn, kernels must absorb (imbibe) about 30 per cent of their weight in water before germination begins (by comparison, soybeans must imbibe about 50 per cent of their weight in water).

Imbibitional chilling injury may result when water colder than 10 C is imbibed, and effects can be particularly severe in situations where seeds were planted into cool soils (10 C or colder), combined with cold rain or melting snow after planting (the most critical time for imbibition is within 24 hours of planting). The absorption of cold water can disrupt the reorganization of cells during rehydration and can result in the loss of seed vigor or seed death. Note: A cold, heavy rain after planting seems to increase the chances of imbibitional injury, probably because it overwhelms the ability of the soil to warm the water before it reaches the seed (Source: Joel Ransom, NDSU).

Symptoms of imbibitional chilling injury include swollen kernels that swell but fail to exhibit further signs of germination or arrested growth of the radicle root and/or coleoptile following the initiation of the germination process.

Instances of non-imbibitional chilling injury following germination during the emergence process can also occur, often causing stunting or death of the seminal root system, deformed elongation of the mesocotyl (the so-called "corkscrew" symptom) and either delayed emergence or complete failure of emergence (i.e., leafing out underground). This type of chilling injury is more closely related to physical damage to the outer cell tissues that literally cause death of the plant part or inhibit further elongation of the affected area. Thus, chilling injury to only part of the circumference of the mesocotyl results in the "corkscrew" symptom as the undamaged sections of the mesocotyl continue to elongate.

The Result of Cold Injury? If germination is impacted, poor stands could result impacting yield potential. Plants that also develop from injured seedlings may be stunted and develop more slowly than normal plants. This can result in unevenness in the growth stages of plants within the field.

 

Optimum corn seed germination occurs when soil temperatures reach 10 C. Cooler temperatures alone are not likely to impose a stress on the seedling, but can delay its emergence. Wet conditions added to cold temperatures following planting will favour development and activity of some soil pathogens that can produce disease stress in the young seedling.

When facing cool planting conditions, other components of successful corn production become more important, such as seedbed condition and planting operations (including planting depth). It is important to keep in mind that rushing the planting operation and planting under less than ideal conditions just to get the crop in can cause problems that can reduce corn yield potential.

Seed Bed Preparation. When preparing the seedbed, producers should try to perform tillage operations only when necessary and under the proper soil conditions. If facing drier than normal soil conditions, try to reduce secondary tillage passes. If secondary tillage operations are needed, perform only when necessary to prepare an adequate seedbed.

Planting Depth. Under most conditions, a planting depth of 1.5 to 2 inches is recommended. When soil temperatures are lower and when soil moisture levels are adequate, producers may want to target planting depths around 1.5 inches. However, it is recommended not to plant less than 1.5 inches deep as some seed may end up much shallower due to variation in the seedbed and/or normal variation in planting depth that occurs. These shallower plantings can result in poor nodal root development that leads to 'rootless' and 'floppy' corn problems, as well as uneven emergence or reduced stands.

When soil moisture is on the drier side, it is not a good idea to plant deeper to chase that soil moisture. Normally good contact between the seed and soil is needed for the seed to take up enough water to allow it to swell and germinate (corn must absorb 30 per cent of its weight in water to germinate). However, planting deeper than 2 inches, especially when soils are cold (i.e., early season, cool season, no-till, etc.), can significantly delay emergence and impact stand establishment.

Final Thoughts. In Manitoba, getting the seed into the ground as early as possible is critical to maximize yield, obtain high quality and low per cent kernel moisture at harvest (which will decrease drying costs), and to ensure the crop is mature before fall frosts.

Hybrids and seed treatments available in today's corn production systems offer some protection from seeding into cooler soils. If planting under less than ideal conditions, adjust the planting operation accordingly. Remember – the planting operation and therefore the number of emerged plants will ultimately set maximum yield potential.

Farmers in the Norfolk sand plain region of Ontario are seeing improved crop yields, thanks to technology that is new to the area. Subsurface drip irrigation irrigates crops via polyethylene drip tubes installed a foot or more underground. This low-pressure, high-efficiency system eliminates surface water evaporation, and reduces the incidence of weeds and disease. And it can increase crop yields.

That’s what was discovered in 2012 when Blake Farms, located south of Simcoe, Ont., completed a small trial comparing non-irrigated, overhead irrigation and subsurface drip irrigation on corn at their farm.
“The non-irrigated corn yielded 35 bushels per acre, overhead irrigated was 163 bushels per acre and the subsurface drip yielded 258 bushels per acre,” Peter White, an irrigation technician from the University of Guelph’s (U of G) Simcoe Research Station says.

It made sense, then, when a nearby broiler and hog operation, Judge Farms, experienced a complete corn crop failure on one of their farms in La Salette the same year and decided they needed an irrigation system, that they would consider a subsurface drip irrigation system. With the knowledge of the trial on Blake Farms, Jim and Robert Judge, owners of Judge Farms, and their farm manager, Todd Boughner, compared the cost of setting up an overhead system – in their case a hard hose traveller – to a subsurface drip irrigation system.

“They felt the cost was going to be comparable for a complete new system of either [an overhead system or a subsurface drip irrigation system]. But the advantages of lower labour and energy costs once installed; the ability to irrigate anytime, day or night, windy or calm; the ability to fertigate throughout the season; and claims of a minimum of 25 per cent better water use efficiency swayed them to install the subsurface drip system in late 2012 and early 2013,” White says.

It was perfect timing for White’s Simcoe Research Station colleagues, John O’Sullivan, a professor in the department of plant agriculture, and research technician Robert Grohs. In early 2013, they received funding from Farm & Food Care Ontario for a Water Resource Adaptation and Management Initiative project.  The idea was to establish 10 plots with an individually controlled, subsurface drip irrigation system, and to monitor the crop at Judge Farms. Others involved in the research included Rene Van Acker, from the U of G, and Ray MacKenzie and Marc Vanden Bussche from Vanden Bussche Irrigation in Delhi, Ont.

All plots, including the subsurface drip irrigated corn fields at Judge Farms, were monitored in 2013 and 2014 for soil moisture, nitrogen (N) use efficiency and yields. The researchers also looked at corn quality on the 10 plots that were set up at the Simcoe Research Station. To do this, soil moisture stations were monitored to assess water depletion by the crop.

“Once soil moistures dropped below 75 per cent of available soil moisture, irrigation was triggered,” White says. “The amount applied was calculated based on evapotranspiration and crop growth stage. Fertility was applied preplant, at planting, sidedressed and through the drip lines, and monitored through tissue sampling.”

It was a very wet year in 2013 compared to 2012 at Judge Farms, which resulted in a yield of 260 bushels per acre of corn on the subsurface drip irrigated field. An adjacent field also harvested by Judge Farms had a yield of 165 bushels per acre.

Over at the Simcoe Research Station, irrigated plots yielded 248 bushels per acre – a 10 per cent increase over the non-irrigated, White says.

“The yields for 2014 were, of course, affected by the amount of rainfall in the area and for sure the lower heat units,” he notes. “The majority of our [2014] rainfall came in July which is the most critical time for moisture stress, so the crop really wasn’t under stress much. We had 6.3 inches of rainfall in July.”

Corn yields at Judge Farms in 2014 were 253 bushels per acre, while their soybean crops hit 70 bushels per acre. There was little difference between plots at the Simcoe Research Station although, White says, numerically the best were irrigated with corn yielding – on average – 183 bushels per acre. The highest yield was 196 bushels per acre at 22 per cent moisture and a bushel weight of 57.3 pounds.

Implications
The researchers believe this technology will allow farmers to grow very successful field crops on soils that have, up until now, only been marginally successful year in year out.

“With the ability to fertigate later into the season, we feel we can obtain much higher yields while not endangering leaching of nutrients,” White says. “The water use efficiency of these systems is so much better than the overhead systems in use right now that we will be able to maintain high yields with less water, resulting in less [negative] effects on the environment.”

What’s next?
Future research plans will narrow the technology gap by focusing on the precise delivery of both water and nutrients. “We need to apply the right amount of both at the right time and not over apply either,” White explains.

Preliminary N fertigation work in 2014 indicates the potential to apply less N while still maintaining high yields. That work will be continued in 2015. “We will get more data on dripper line spacings and that will give us a chance to evaluate the returns we get for the costs involved,” White says. “All subsurface drip irrigation users will need time to gain the knowledge needed to use the system to the best of its ability and gain confidence in this technology.”

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