NITROGEN APPLICATION RATES

Nitrogen Management Practices to Improve Crop Nitrogen Use Efficiency and Minimize Nitrogen Losses to the Environment

Basic recommended rates are determined based on your soil test report by looking at the planned crop and the expected yield for that crop. The amount of residual nitrogen in the soil must then be taken into account and subtracted from the recommendation. This includes previous manure applications and carryover N from previous legumes. Also, if fertilizer, such as a starter containing N, is applied regardless of manure applications, this N should also be taken into account. You need to account for these credits by subtracting them from the basic soil test recommendation (Figure 2). The resulting number will give you the rate you need to apply this year as fertilizer, manure, or other source of N.

Net Crop Nitrogen Requirement
Figure 2. Net crop nitrogen requirement.

  • Do not apply nitrogen in excess of crop recommendations. Having an approved nutrient management plan can help you with this. See your soil test for the recommended rate and be sure to take into account the planned incorporation time, previous manure, and legumes.
  • Manure application rates should be based on meeting the net crop need after all other sources of N either in the soil (legume N, manure residual N) or added N (starter fertilizer, N applied with herbicides) have been accounted for.
  • Manure N availability to the crop is lower than the total amount of N in the manure. Thus, more total manure N must be applied to achieve the same results as would be needed using fertilizer to meet the same net crop requirement. However, manure N availability increases with optimum manure application management. The goal for optimum manure N management is to reduce the total N applied in manure to as close as possible to the amount that would be required as fertilizer.
  • Best management such as applying manure in the spring, incorporating it immediately following application, and cover cropping will generally result in the highest manure N availability, less than two times the amount of fertilizer N that would be required to meet the net crop requirement. With good manure management, the total amount of manure N applied should be less than three times the fertilizer N requirement to meet the net crop requirement. Acceptable but less efficient manure N management may require more than three times the total manure N compared to fertilizer to meet the net crop requirement. See the Manure Nutrient Management section of the Penn State Agronomy Guide for information and instructions for making these critical calculations.
  • Use the PSNT (pre-sidedress soil nitrate test) or chlorophyll meter to guide sidedress fertilizer nitrogen applications. The PSNT measures nitrate in the soil right before the highest amount of crop uptake. The chlorophyll meter test estimates the nitrogen status of growing corn by measuring the greenness of the leaves. Both of these in-season tests improve N recommendations significantly in most situations, particularly when manure is being used.
  • Where appropriate, use new technologies such as on-the-go sensors and aerial photography that can provide useful information about the N status of crops, improve N recommendations, and enable variable-rate N application. Variable-rate N application has potential to improve crop yields and limit N environmental losses based on crop growth status and its interpretation for changing N rate application versus the traditional whole-field uniform-application-rate approach. Keep up on the latest technologies as they are developed and evaluated, and determine how they might fit into a program to improve N management on your farm.

SOURCE: PENN STATE EXTENSION

The Role Of Gypsum In Agriculture: 5 Key Benefits You Should Know

While farmers have used gypsum (calcium sulfate dihydrate) for centuries, it has received renewed attention in recent years. This resurgence is due in large part to ongoing research and practical insights from leading experts that highlight the many benefits of gypsum.

The latest information on gypsum has been covered in detail at past Midwest Soil Improvement Symposiums. The event — which has been held in conjunction with The Ohio State University’s Conservation Tillage and Technology Conference — typically includes presentations from industry representatives, scientists, consultants, and growers on the use of gypsum to improve soil structure, reduce nutrient runoff, and more.

Here are five key (and overlapping) benefits of gypsum highlighted at past symposiums:

1. Source of calcium and sulfur for plant nutrition. “Plants are becoming more deficient for sulfur and the soil is not supplying enough it,” said Warren Dick, soil scientist and professor, School of Environment and Natural Resources, The Ohio State University. “Gypsum is an excellent source of sulfur for plant nutrition and improving crop yield.”

Meanwhile, calcium is essential for most nutrients to be absorbed by plants roots. “Without adequate calcium, uptake mechanisms would fail,” Dick said. “Calcium helps stimulate root growth.”

2. Improves acid soils and treats aluminum toxicity. One of gypsum’s main advantages is its ability to reduce aluminum toxicity, which often accompanies soil acidity, particularly in subsoils. Gypsum can improve some acid soils even beyond what lime can do for them, which makes it possible to have deeper rooting with resulting benefits to the crops, Dick said. “Surface-applied gypsum leaches down to to the subsoil and results in increased root growth,” he said.

3. Improves soil structure. Flocculation, or aggregation, is needed to give favorable soil structure for root growth and air and water movement, said Jerry Bigham, Professor Emeritus, School of Environment and Natural Resources, The Ohio State University. “Clay dispersion and collapse of structure at the soil-air interface is a major contributor to crust formation,” he said. “Gypsum has been used for many years to improve aggregation and inhibit or overcome dispersion in sodic soils.”

Soluble calcium enhances soil aggregation and porosity to improve water infiltration (see below). “It’s important to manage the calcium status of the soil,” he said. “I would argue it’s every bit as important as managing NPK.”

In soils having unfavorable calcium-magnesium ratios, gypsum can create a more favorable ratio, Bigham added. “Addition of soluble calcium can overcome the dispersion effects of magnesium or sodium ions and help promote flocculation and structure development in dispersed soils,” he said.

4. Improves water infiltration. Gypsum also improves the ability of soil to drain and not become waterlogged due to a combination of high sodium, swelling clay and excess water, Dick said. “When we apply gypsum to soil it allows water to move into the soil and allow the crop to grow well,” he said.

Increased water-use efficiency of crops is extremely important during a drought, added Allen Torbert, research leader at the USDA-ARS National Soil Dynamics Lab, Auburn, AL. “The key to helping crops survive a drought is to capture all the water you can when it does rain,” he said. “Better soil structure allows all the positive benefits of soil-water relations to occur and gypsum helps to create and support good soil structure properties.”

5. Helps reduce runoff and erosion. Agriculture is considered to be one of the major contributors to water quality, with phosphorus runoff the biggest concern. Experts explained how gypsum helps to keep phosphorus and other nutrients from leaving farm fields. “Gypsum should be considered as a Best Management Practice for reducing soluble P losses,” said Torbert, who showed studies on how gypsum interacts with phosphorus.

Darrell Norton, retired soil scientist at the USDA-ARS National Soil Erosion Research Laboratory at Purdue University, added: “Using gypsum as a soil amendment is the most economical way to cut the non-point run-off pollution of phosphorus.”

SOURCE: CROPLIFE

NUTRIENT MANAGEMENT (PART 2)

NUTRIENT BUDGETING

Budgeting is fundamental to BMP for nutrients. First, the budget must take into account the amount of nutrients a grower expects the crop to take up and, subsequently, leave the system in the crop biomass. This amount will vary among crop species as well as among levels of productivity within the same species. For example, a corn crop that yields 100 bushels/acre (5600 lbs) will export (meaning that nutrients leave the field in the harvested portion of the plant) approximately 80 lb/acre of N in the grain and 60 lbs/acre of N in the stover (which is above-ground biomass that is not grain and includes stalks/stems and leaves). If the corn crop were to yield 80 bushels/acre, those numbers would be reduced by 20%. Compare that with an iceberg lettuce crop that yields 40,000 lbs/acre. This will export approximately 80lbs/acre of N from the field, all in the above-ground biomass (since the whole above-ground portion of the plant is harvested). How does one figure such numbers out? There is information available for prominent crops via extension services and other online tool. However, it is also possible to estimate these numbers by multiplying the concentration of a nutrient by the quantity of biomass that contains that concentration. (For example: Corn grain contains about 1.4% N at harvest. Therefore, for a 3 ton/acre crop, the amount of N leaving the field in the grain is 6000lbs x 0.014 = 84lbs/acre N.

In order to anticipate the amount of nutrients likely to be exported from the field in the crop biomass, a grower must consider in advance what a reasonable yield goal is for the crop s/he is growing. If the grower has had previous experience with the crop at the same location, this is often a good guide. Also, trying to get a general idea of typical yields for the crop and region in question can be an important step. This information might be gained by consulting with other growers, with a professional crop consultant, and/or a university extension agent, such as the UCANR Statewide Integrated Pest Management Program, the UC Vegetable Research and Information Center, the UC Manure Management Crop N Uptake Calculator and the UCANR Soil Fertility Management Guide for Fresh Market Tomato and Pepper Production. It is important that the yield goal not be a “yield wish”. Fertilizing for a crop yield that is not attainable in a given context (due to inherent biophysical and/or management constraints) is a very easy way to over-budget the fertility needed and create an opportunity for nutrient pollution in connected water bodies.

No crop will use fertilizers with 100% efficiency. In fact, 60-70% efficiency is generally as good as can be accomplished, and many of the most common crops grown in California are estimated to have much lower average efficiencies. The reasons are that 1) plants are often in competition for nutrients with the micro-biota in the soil and 2) nutrient losses via the movement of water and gas are an inherent part of a dynamic, productive biological environment. However, applied fertility that goes unused by a given crop can still be incorporated into the plant-soil system by using cover cropsrotating with crops that have distinct root systems and nutrient uptake patterns, and by other management practices that are soil building. A fertile soil with a high nutrient supplying capacity can compensate for a fertilizer deficiency in the short to medium-term. Conversely, a less fertile soil may require more applied nutrients than the above ground portion of the crop will use in order to account for the fertilizer use inefficiency and the low nutrient supplying capacity of the soil. For this reason, soil fertility testing is an important part of determining the right amount of nutrients to add. However, interpretation and application of soil tests varies greatly from crop to crop and across environments.

SOURCE: California Agricultural Water Stewardship Initiative

NUTRIENT MANAGEMENT (PART 1)

Nutrient management is among the most consequential decisions that a grower makes with respect to water quality and crop productivity. Because crops do not take up fertilizer with 100% efficiency, many growers apply organic and inorganic fertility in excess of crop demand to ensure that nutrients are not limiting to their crops. While this is often an economic decision, adding excess nutrients to the crop-soil system also creates an opportunity for nutrient losses from farms into the surrounding environment. One major loss pathway for excess nutrients is via nutrient-enriched water that drains from the surface of agricultural fields or percolates beyond the root zone of the crop and into groundwater storage. Nitrogen (N) and phosphorus (P) are generally the most limiting nutrients to crop growth, and are, therefore, added in the greatest quantities by growers and most frequently the nutrient constituents of concern in agriculturally connected waterways and aquifers. When present in excess, nitrates and phosphates can create environmental problems such as eutrophication of waterways, algal blooms, and contamination of drinking water. Recent research in the Tulare Basin and Salinas Valley has found that nitrate pollution of groundwater supplies is widespread and overwhelmingly the result of the agricultural activities in the area over the past six decades. As a result of this study, new regulations on N management have been introduced and are being phased-in throughout the state. The objectives of these regulations are to maintain crop productivity while also reducing environmental pollution due to the over-application of plant nutrients.

Fortunately, managing nutrients to optimize crop growth and water quality are not mutually exclusive. Applying the Right Amount of fertility, at the Right Time, to the Right Place, in the Right Form (4Rs) is likely to maximize the amount of fertilizer that is taken up by the crop and minimize the amount of fertilizer that is wasted or lost to the environment. Since the application of fertilizers is generally one of the highest input costs in agricultural systems, this approach saves farmers money while reducing their environmental footprint in surrounding bodies of water. However, such best management practices (BMP) tend to be highly specific to the crop and environment where they are applied. Further, they involve not only management of the nutrients themselves, but also the interaction of the nutrients with water that is added to the crop-soil system (whether via irrigation or rainfall). Therefore, BMP should be governed by a few fundamental principles, but adapted to the particular cropping context where they are applied. The objective of this practice page is to outline several of the key principles for managing nutrients to maintain water quality without sacrificing crop productivity. Also included are links to resources that will assist in better understanding and implementing BMP as well as links to case studies that exemplify context-specific applications of BMP.

SOURCE: The California Agricultural Water Stewardship Initiative

The Nitrogen Cycle: What You Should Know

Nitrogen (N) makes up 78 percent of the air we breathe in the form of nitrogen gas (N2), but this form is unable to be used by plants. In fact, there are 34,000 tons of N in the air above an acre of land, but none of it can be used by crops. Nitrogen must be fixed in order to become available, which is done through the process of making industrial fertilizers or through nitrogen-fixing bacteria associated with the roots of legumes. A significant amount of nitrogen occurs in the soil naturally (2,000–4,000 pounds per acre, lbs/A), but 98 percent of that nitrogen is in the organic form and also cannot be used by plants. This organic nitrogen is found in all living and previously living material in the soil. Nitrogen naturally becomes available in soil as organic matter is mineralized, which results in around 60–80 pounds of nitrogen per acre per year for crop uptake. Two forms of inorganic nitrogen are plant available: ammonium N (NH4+) and nitrate N (NO3). Ammonium N is held on the soil particles and can be exchanged with other cations in order for plants to take it up, but it does not leach easily from the soil. Nitrate N, on the other hand, is found in the soil solution and can be leached from the profile. Nitrogen leaching needs to be managed properly to ensure that plants have access to the nitrate and also to minimize the nitrate pollution in waterways. Understanding the nitrogen cycle thoroughly allows us to do that. The processes involved in the cycle are summarized below.

The forms of nitrogen, the transformations that it undergoes in the soil, and the nitrogen loss pathways are summarized in the N cycle (Figure 1). Most of the transformations in the N cycle are the result of microbial activity. Because these are biological processes, they are very sensitive to the environment where they occur. Major factors influencing these processes are temperature and moisture and thus the weather. The challenge with managing N is to achieve maximum N availability when crops need N and to reduce loss of N to the environment. The goal is to minimize soluble forms of N when at times of little or no crop uptake. This can be achieved by understanding the N cycle and managing inputs. The three main pathways of N loss are nitrate leaching, denitrification, and volatilization, discussed below.

Nitrogen Cycle
Figure 1. Nitrogen cycle: Transformations between N forms.

SOURCE: Penn State Extension

Water management grows farm profits

A healthy lifestyle consists of a mixture of habits. Diet, exercise, sleep and other factors all must be in balance. Similarly, a sustainable farm operates on a balanced plan of soil, crop, and water management techniques.

Man installing soil moisture sensors.

Soil moisture sensors aid in advanced irrigation scheduling and help measure water consumption on farm fields. Photo credit: Matt Yost

The western United States is a region with scarce water resources. In this case, water management techniques make up a larger piece of a sustainability plan. There is mounting concern around the globe about water scarcity. This is due to urban sprawl, depleting water supplies in some areas, and predicted water shortages in the future with less snowpack.

Water management techniques that lead to the optimal use of limited resources are not well-identified. Yet. Matt Yost, a researcher at Utah State University, is working to find the best combination of practices to maximize yield, profit, and water efficiency.

“Most cropland in Utah and the western United States is irrigated,” explains Yost. “There are areas where groundwater from aquifers is being used faster than it can be replaced. Some of these areas are under intense pressure to conserve water.”

Water for irrigation comes from aquifers far below the farm’s surface. Aquifers are naturally refilled by water from the surface by precipitation. Increased water use can lower the water table. Eventually wells can go dry. These factors make water optimization crucial for food security.

Irrigation pivot in field.

Pivot technology trial in Central Utah. From left to right: low elevation spray application (LESA), mid-elevation spray application (MESA), and mobile drip irrigation (MDI). Photo credit: Matt Yost

Yost researches many water management techniques. These include using irrigation scheduling and advanced pivot irrigation technology. In addition, his team researches crop and soil management practices. They look at rotating in drought-tolerant crops, cover crops, and reduced tillage.

Yost’s team works together with many farmers across Utah to do farm-scale trials.

“Irrigation research is tough and costly on farmer’s fields,” says Yost. “It’s especially true when it comes to irrigation scheduling. Though difficult, this on-farm research and collaboration is crucial for the understanding and adoption of new water optimization techniques.”

So, what is the best combination of management techniques to maximize yield, profit, and water efficiency? The answer isn’t clear, yet. Results and analyses are still pending, but Yost offers some initial recommendations:

  • Advanced pivot irrigation technologies, such as mobile drip and low-energy precision application or spray application, are beneficial. They can usually maintain crop yields with about 20% less applied water.
  • Most farmers may be able to reduce irrigation rates by 10% without affecting crop yields.
  • Biochar applications are showing few short-term crop yield or water saving benefits.

Pivot irrigation in field with drip irrigation.

Advanced pivot irrigation systems such as mobile drip irrigation, low-energy precision application and low-energy spray application reduce wind drift and evaporation – allowing for reduced irrigation rates. Photo credit: Jonathan Holt

“We are beginning to answer questions about new irrigation techniques and scheduling approaches,” says Yost. “But many still exist for discovery.”

Next, Yost and his team hope to secure funding for long-term irrigation research sites. Water is a limited and vital resource. Strategies to optimize water use will be crucial to the sustainability of irrigated agriculture.

“In irrigated agriculture, agronomy and irrigation go hand-in-hand,” explains Yost. “Nearly everything about one influences the other. Most irrigation programs focus more on engineering than on irrigation science. With my original training in agronomy, I’ve noticed knowledge gaps and have identified opportunities to unite irrigation science and agronomy.” Yost’s unique perspective offers a holistic approach to integrated water, soil, and crop management.

SOURCE: Crop Science Society of America. Dec 2, 2019

6 Major Changes that Will Shape Agriculture in the 2020’s

With another new year coming in, it is always a good time to start reflecting on the previous year and looking ahead to what is next. As we come into the new decade of the 2020s, it is interesting to think about what is to come with the future of agriculture in the next 10 years. We are now 30 years from the 2050 deadline we all hear about and have significant opportunity to combat challenges in our industry in the next decade.

So, what’s next for the future of agriculture?

The next 10 years will bring about some exciting advancements, opportunities, and challenges. Below are a few of the categories and changes we might see in the coming years. No one can predict the future, but based on current trajectory of technologies and agribusiness, some of the changes we may see in the next few years are significant to our industry.

Technology

This is one near and dear to many of our hearts in precision agriculture and digital farming, but instead of looking at the next satellite resolution or the sensor to the future, looking at how the technology is used and adopted in the next 10 years is critical. For more adoption and use, the next decade will have to bring technology that is available, affordable, and usable. Having more bells and whistles only matters if we can trace back or realize an immediate ROI on the farm for the decisions that we are making.

The technology advancements already available are astounding but cost or use is prohibitive to making everyday decisions when margins are tight. We will continue to hear about AI, machine learning, sensors and IoT, data management, and the technologies will move more into everyday use than in an early adopter or innovator phase. “The Global Artificial Intelligence in Agriculture Market Analysis” projects the market to grow at a significant CAGR of 28.38% during the forecast period from 2019 to 2024 alone. These technologies and advancements for our sector of agribusiness will grow and advance significantly in the next 10 years.

Automation

As connectivity, rural broadband accessibility, and technology intelligence gets better and better, automation is on track to make revolutions in the next 10 years — with both equipment, implements, and decision making alone.  The market for agriculture is expected to grow from USD 11.2 billion in 2018 to USD 20.9 billion by 2024; it is projected to grow at a CAGR of 10.4% from 2019 to 2024.

We’ve all seen the autonomous cars and models of tractors, but the next decade may bring more automation outside of the box than we have seen before as technology, connectivity, and data science improves. Automatic irrigation systems based on weather and crop demands, more storage fans and temperature controls automatic, automated job creation, and easier alerting on potential threats to production or marketing are all in the pipeline now across agribusiness but may become more available and confident in the next decade.

Size

Size of everything in the next 10 years is certain to change. As the next decade will more than likely be a turn from an older generation of farmers to the younger and new generation, many decisions on size — from equipment, to farms, to labor — all will change in the 2020s, based on need or opportunity from a new generation of decision makers.

Will farms be more apt to consolidation and getting larger, or will smaller farms create niche marketing opportunities to sell to their consumers? If farms do get larger, do we see less price volatility due to risk management of utilizing precision technologies and a more global scale of reliable production? Where does global production move by commodity with more advancements not only domestically, but internationally? With equipment, can we get any larger, or do smaller, swarm-type fleets begin to make the main stage on the farm in 2020-2030? Will labor pools decrease as the move from rural to urban areas continues into the next 10 years? Many unanswered questions surround size in the coming years.

Transparency

We continue to hear about transparency, especially the last few years about things like blockchain, consumer demand, and regulation. In the next decade, these terms may become more about what is happening as the “norm” and less about buzzwords. With easier data collection on farm, opportunities to sell to specific consumers for food, fiber, or fuel sources may drive more consumer interest from the farm. As regulation continues with government interest in topics such as climate change or water availability, providing records and the bread crumb trail of production could become a necessity for all farms to produce and sell into an open market. Having data records available for audits, insurance, financing, and others, create new opportunities for farms to be better prepared for the tasks ahead.

Business

As the modern farms of the next 10 years change, agribusiness surrounding and supporting them will also start to see shifts in the day-to-day functions. We’ve already seen announcements on new pricing models, such as outcome-based pricing, and beginning to see more suppliers and retailers move to offering e-commerce platforms for customers to purchase inputs and supplies. Another large event that we witnessed the last decade that will continue into the 2020s will be the consolidation of businesses, whether by merger or acquisition. Investments in ag technology are still high and maturing as well. Last year was a “record breaking year” for the industry that included $16.9 billion in funding spread across 1,450 investments, and it doesn’t look like it is slowing down. New market opportunities both for businesses to begin supporting new farmers and emerging areas will be opening, as well as new opportunities for supporting business in growing countries such as India and Brazil.

Support

The key component to everything we do in agribusiness and technology is support, and that component won’t end in the future. Technology won’t replace good people — farmers, agronomists, sales people, etc. — only help to contribute to make things easier, more effective, and more impactful. New farmers will need help navigating a complex world of decisions, new generations of students and enthusiasts will come into our world, and we will continue to grow and collaborate to better our industry for the future. There is nowhere more exciting than agriculture right now, and the next 10 years will continue that path.

No one can see the future, but as we move forward into the next decade it is exciting to see where we have come from in agriculture and where we are going. The last 100 years have been a whirlwind, and to think of the advancements coming is exciting and a challenge for all of us in agriculture to foster adoption of technology but also of change as we work towards our goal of providing profitable farms and a sustainable world.

SOURCE: Digital Farming January 2, 2020

Growers Are Using Drones To Help Save The Colorado River

A drone soared over a blazing hot cornfield in northeastern Colorado on a recent morning, snapping images with an infrared camera to help researchers decide how much water they would give the crops the next day.

After a brief, snaking flight above the field, the drone landed and the researchers removed a handful of memory cards. Back at their computers, they analyzed the images for signs the corn was stressed from a lack of water.

This Department of Agriculture station outside Greeley and other sites across the Southwest are experimenting with drones, specialized cameras and other technology to squeeze the most out of every drop of water in the Colorado River – a vital but beleaguered waterway that serves an estimated 40 million people.

In this Thursday, July 11, 2019, photograph, United States Department of Agriculture engineering technician Kevin Yemoto guides a drone into the air at a research farm northeast of Greeley, Colo.

Remote sensors measure soil moisture and relay the readings by Wi-Fi. Cellphone apps collect data from agricultural weather stations and calculate how much water different crops are consuming. Researchers deliberately cut back on water for some crops, trying to get the best harvest with the least amount of moisture – a practice called deficit irrigation.

“It’s like almost every month somebody’s coming up with something here and there,” said Don Ackley, water management supervisor for the Coachella Valley Water District in Southern California. “You almost can’t keep up with it.”

Researchers and farmers are running similar experiments in arid regions around the world. The need is especially pressing in seven U.S. states that rely on the Colorado River: Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming.

In this Thursday, July 11, 2019, photograph, United States Department of Agriculture intern Alex Olsen, left, and engineering technician Kevin Yemoto work to set up a drone for flight over a research farm northeast of Greeley, Colo.

The river has plenty of water this summer after an unusually snowy winter in the mountains of the U.S. West. But climatologists warn the river’s long-term outlook is uncertain at best and dire at worst, and competition for water will only intensify as the population grows and the climate changes.

The World Resources Institute says the seven Colorado River states have some of the highest levels of water stress in the nation, based on the percentage of available supplies they use in a year. New Mexico was the only state in the nation under extremely high water stress.

The river supplies more than 7,000 square miles of farmland and supports a $5 billion-a-year agricultural industry, including a significant share of the nation’s winter vegetables, according to the U.S. Bureau of Reclamation, which manages most of the big dams and reservoirs in the Western states.

The Pacific Institute, an environmental group, says the river also irrigates about 700 square miles in Mexico.

Agriculture uses 57% to 70% of the system’s water in the U.S., researchers say. The problem facing policymakers is how to divert some of that to meet the needs of growing cities without drying up farms, ranches and the environment.

The researchers’ goal is understanding crops, soil and weather so completely that farmers know exactly when and how much to irrigate.

“We call it precision agriculture, precision irrigation,” said Huihui Zhang, a Department of Agriculture engineer who conducts experiments at the Greeley research farm. “Right amount at the right time at the right location.”

The Palo Verde Irrigation District in Southern California is trying deficit irrigation on alfalfa, the most widely grown crop in the Colorado River Basin.

Alfalfa, which is harvested as hay to feed horses and cattle, can be cut and baled several times a year in some climates. The Palo Verde district is experimenting with reduced water for the midsummer crop, which requires more irrigation but produces lower yields.

Sensors placed over the test plots indirectly measure how much water the plants are using, and the harvested crop is weighed to determine the yield.

“The question then becomes, what’s the economic value of the lost crop versus the economic value of the saved water?” said Bart Fisher, a third-generation farmer and a member of the irrigation district board.

Blaine Carian, who grows grapes, lemons and dates in Coachella, California, already uses deficit irrigation. He said withholding water at key times improves the flavor of his grapes by speeding up the production of sugar.

He also uses on-farm weather stations and soil moisture monitors, keeping track of the data on his cellphone. His drip and micro-spray irrigation systems deliver water directly to the base of a plant or its roots instead of saturating an entire field.

For Carian and many other farmers, the appeal of technology is as much about economics as saving water.

“The conservation’s just a byproduct. We’re getting better crops, and we are, in general, saving money,” he said.

But researchers say water-saving technology could determine whether some farms can stay in business at all, especially in Arizona, which faces cuts in its portion of Colorado River water under a drought contingency plan the seven states hammered out this year.

Drone-mounted cameras and yield monitors – which measure the density of crops like corn and wheat as they pass through harvesting equipment – can show a farmer which land is productive and which is not, said Ed Martin, a professor and extension specialist at the University of Arizona.

“If we’re going to take stuff out of production because we don’t have enough water, I think these technologies could help identify which ones you should be taking out,” Martin said.

Each technology has benefits and limits, said Kendall DeJonge, another Agriculture Department engineer who does research at the Greeley farm.

Soil moisture monitors measure a single point, but a farm has a range of conditions and soil types. Infrared images can spot thirsty crops, but only after they need water. Agricultural weather stations provide a wealth of data on the recent past, but they can’t predict the future.

“All of these things are tools in the toolbox,” DeJonge said. “None of them are a silver bullet.”

SOURCE: Soil and Water Conservation Society. 2 January 2020

World Ag Productivity Growth Is Slow

Agricultural productivity growth, a measure of the increased output of crops and livestock with existing or fewer inputs, is not keeping pace with global demands, according to the newly released 2019 Global Agricultural Productivity (GAP) Report.

Agricultural productivity growth is growing globally at an average annual rate of 1.63%. However, the report’s GAP Index shows that global agricultural productivity needs to increase at an average annual rate of 1.73% to sustainably produce food, feed, fiber and bioenergy for 10 billion people in 2050.

The report, which examines the pivotal role of agricultural productivity in achieving global goals for environmental sustainability, economic development, and improved nutrition, was released at the World Food Prize in Des Moines, Iowa on Oct. 15 by Virginia Tech’s College of Agriculture and Life Sciences.

While productivity growth is strong in China and South Asia, it is slowing in the agricultural powerhouses of North America, Europe and Latin America, the report’s authors said in a press release.

In addition, the findings show very low levels of productivity growth in low-income countries, where there are also high rates of food insecurity, malnutrition and rural poverty. Agricultural productivity growth in low-income countries is rising at an average annual rate of just 1%, the report warned. The United Nations’ sustainable development goals call for doubling the productivity of the lowest-income farmers by 2030.

“These productivity gaps, if they persist, will have serious ramifications for environmental sustainability, the economic vitality of the agriculture sector, and the prospects for reducing poverty, malnutrition and obesity,” said Ann Steensland, author of the 2019 GAP Report and coordinator of the GAP Report Initiative at Virginia Tech.

Historically, productivity growth has been strongest in high-income countries such as the United States, with significant environmental benefits. Due to widespread adoption of improved agricultural technologies and best farm management practices, global agricultural output has increased by 60%, while global cropland has increased by just 5% during the past 40 years, according to the report.

Between 1980 and 2015, productivity gains led to a 41% decrease in the amount of land used in U.S. corn production, irrigation water use declined 46%, greenhouse gas emissions declined 31%, and soil erosion declined by 58%.

The report also shows that animal agriculture in the U.S. has experienced similar productivity gains, dramatically reducing the environmental footprint of livestock production. According to Robin White, assistant professor of animal and poultry science at Virginia Tech, if livestock production in the U.S. was eliminated, total U.S. greenhouse gas emissions would decline by only 2.9%.

SOURCE: www.eco-gem.com/world

Are California Farmers Water Hogs?

In his commentary in the Wall Street Journal, California Farmers Aren’t the Water Hogs, Ted Sheely discusses the blame farmers are asked to take for the water shortage in California.

Sheely, a farmer himself in California’s San Joaquin Valley, argues that the media is not reporting the full picture.

“The second-worst thing about the drought is how farmers are bearing most of the blame. We hear one figure over and over: Agriculture consumes 80% of California’s water.

That statistic makes farmers like me look like gluttons—and it suggests that if we were to reduce our reliance on water just a little, then our state’s predicament would vanish like a puddle on a hot day.

Except that it’s not true. Farmers don’t use 80% of California’s water. While this figure has saturated the media’s coverage of the drought—it’s a fabrication of environmentalists who want to disguise that they “use” even more water than farmers.”

FarmlandFarmland

Farmland in Los Banos, Calif., in the San Joaquin Valley. PHOTO: LUCY NICHOLSON/REUTERS

Read the entire story in the Wall Street Journal: California Farmers Aren’t the Water Hogs