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There are 5 ways that proven AquaSpy layer by layer soil moisture technology improves crop yield and soil health that you might not have thought of:

1. Salinity management
2. Flash drought alerts
3. Lodging prevention
4. Cover crop management
5. Regenerative field trials

Salinity Management

Salt-affected soils reduce water use efficiency which causes poor plant health, resulting in reduced yields, or at the worst, causing crop loss. While many growers can visibly spot white salt deposits or crusts visible at the soil surface, salinity occurs at various depths in the soil, and may not be visible to the eye. Excessive soil salinity has become a severe problem for growers in several parts of the U.S. including Florida, Texas High Plains/Rio Grande and California Central Valley. Successive years of drought have forced growers to rely on irrigation water, which can contain salts. If the salts are not leached out of the soil by rainwater or other clean water source, then the salts accumulate, and salinity increases.

Deciduous fruits, nuts, citrus and avocado are among the most salt sensitive crops. Soil salinity can affect crops in three ways; the salty soil draws water from the plants through osmosis, making it difficult for plants to uptake water, increased levels of sodium in particular can alter the structure of the soil, causing the soil surface to transform from flocculated to dispersed, forming a barrier to water infusion, and last there can be specific ion toxicity with certain crop plants and certain soils. AquaSpy understands the relationship between crop health and salinity and includes layer by layer EC salinity measures so growers in impacted regions can keep a close eye on their crops throughout the season, during droughts, and after heavy coastal storms.

Lodging Prevention in Corn and Maize

Timely soil moisture management to prevent stress from water logging or too dry conditions can help prevent stalk lodging in corn and maize. Stalk lodging is the breakage of the stalk below the ear and is a serious problem that can lead to harvest yield losses. Stalk rot resulting from water logging in corn and maize weakens the stalk tissue and can leave the plant more susceptible to breakage.  A number of issues can occur that impact yield when the plant can no longer take up available water. It’s important to minimize plant stress by avoiding extremes in soil moisture as well as nutrient deficiencies caused by N loss or leaching. Closely monitoring soil moisture throughout the growing season ensures that the crop only gets the moisture it needs, layer by layer, which prevents water-logged soils and excess runoff in addition to giving the ability to monitor the crop’s uptake of available moisture throughout the season.

Flash Drought Alerts

A flash drought is when very warm surface temperature paired with an unusually low and decreasing soil moisture leads to rapid drying. Rather than season long droughts that develop over a long period, flash droughts can take hold in just a few weeks so they are more difficult to forecast. Recent memorable flash droughts occurred in 2012, 2017 and 2019, causing billions of dollars of losses for unprepared growers in the affected regions. For growers who are using continuous below ground soil moisture sensors that record soil temperature, soil moisture and crop moisture uptake, they will be able to notice the quickly dropping soil moisture levels in real time, giving them a chance to react. It’s important to set your alerts so that you can know right away that flash drought conditions are setting up.

Cover Crop Management

There has been growing interest in how to incorporate cover crops with corn and soybean rotation as a strategy to promote soil health by reducing soil erosion and nutrient loss. However, a number of questions have been raised as to where cover crops might increase water requirements in already constrained areas. While cover crops will use some water, there is a net overall benefit from keeping the ground covered that includes increased water infiltration and retention, reducing water runoff and reducing evapotranspiration. A 3 year study done at UC Davis found that cover crops did not compete with cash crops (in this case tomato and almond) for water and that the same amount of water used in the control fields without cover crops was able to support the same amount of crop yield in the cover crop fields. A meta analysis of research from around the world shows that results may not be consistent in all regions so it may be useful to run your own season long comparison. You can consult with your local university, extension or cooperative or if you want to conduct trials in your own fields, you can use soil moisture monitoring technology with temperature, infiltration and consumption reports to establish a baseline and then provide real time side by side – and layer by layer! – data to inform your practices based on your own field and crops.

Regenerative Agriculture Field Trials

There is a lot of buzz around sustainable and regenerative practices, though some growers continue to take a cautious approach before making wholesale switches. We talked about cover cropping above and that’s one area where growers have questions about what impact cover crops have and how it changes their water usage. Growers have similar questions around other regenerative practices such as zero / low tillage, crop rotation and managed grazing.

You can use AquaSpy layer by layer soil moisture technology to run concurrent field tests in your own region, climate, soil type, and crops. With AquaSpy soil moisture technology, you’ll be able to make side by side comparisons of what’s happening in the root zone and how the crop is responding:

• Available soil moisture every 4 inches
• Crop utilization of available moisture every 4 inches
• Soil temperature
• Infiltration
• Consumption

What’s unique about AquaSpy’s approach to soil moisture monitoring

AquaSpy looks layer by layer into the soil and can see what’s occurring at the active root zone. This insight is critical for crops which need to have water where and when it’s needed most.

Patented multi-sensor probes measure soil moisture, salinity, temperature and root zone activity independently at 4-inch intervals all the way down to 48 inches. Proprietary algorithms give yield-optimizing insights for ideal irrigation at critical growth stages that impact the outcome of crop yields. The powerful AgSpy system provides analysis and actionable insights so growers can easily understand what is going on without having to visit the orchard or farm.

Visit AquaSpy.com to learn more or visit the AquaSpy Booth #413 at Tech Hub Live 2024 in Des Moines.

Every state in the contiguous United States is experiencing some level of nitrate contamination that is causing chemical buildup in rivers, lakes, oceans and groundwater. Those states showing the most widespread drinking water contamination to date are California, Illinois, Iowa, Kansas, Maryland, Nebraska, Oklahoma, Pennsylvania, Texas and Wisconsin. Many states in river headland areas have started educational programs with regional growers so they are better informed about how to avoid soil runoff and soil leaching using process control and precision irrigation management techniques.

California

California leads the nation in total agriculture, producing a third of the country’s vegetables. California has battled groundwater contamination for many years. A 2012 report commissioned by the state and developed by UC Davis focused on heavy agricultural areas within the state, and showed that groundwater contamination by nitrates from agriculture had exceeded safe levels in groundwater for many communities. The report further determined that mitigation of nitrogen by pumping and cleaning was not economically feasible, and that it would take decades to produce meaningful reductions of nitrates in the groundwater.

Chemical nitrogen reporting requirements matched to harvest estimates are now required for all of California’s Central Valley. The state is recommending that growers pumping groundwater for irrigation should minimize excess water not taken up by plant roots and that growers should make efforts to reduce application of excess chemical nitrogen past the needs of plants for optimal yield for the nitrates invested.

Nebraska

Farms and ranches comprise 92% of Nebraska’s total land area. Over 1/3 of the farmland produces annual crops (corn, wheat, soy etc.). For many years the University of Nebraska—Lincoln has studied the effects of nitrate on groundwater and the mechanics of soil leaching, resulting in many of the nitrate-conserving practices in general use. The Nebraska water Center at UNL conducts regular surveys, develops reports/seminars and advises growers on best conservation practices.

Recent legislation being considered by the State would incentivize growers to “implement a program to incentivize farmers to switch from synthetic fertilizers to sustainable alternatives, such as nitrogen-fixing bacteria.”

Mississippi

For states like Mississippi that enjoy adequate although uneven average rainfall, waterlogging can prevent water from draining down to the water table, carrying nitrate with it, and as a result nitrogen loss is largely due to ammonification and denitrification. Mississippi does not yet have a problem, but with climate change, drought conditions in the upper Mississippi River valley and longer than usual local droughts the situation requires monitoring. The National Center for Alluvial Aquifer Research operated jointly by Mississippi State and The USDA’s Agricultural Research Service works to ensure water quality for the state.

Colorado

Colorado’s Agricultural Chemicals and Groundwater Protection Program (Groundwater Program) has sampled groundwater from wells in Colorado since 1992. Colorado has 250,000 wells, four out of five of which are small residential wells. The Groundwater Program focuses primarily on wells in agricultural areas of the state. Results from 1992 to 2015 show that 23% of wells sampled had nitrate contamination over the EPA recommended standard.

Colorado’s program for groundwater management is voluntary, and based on a vulnerability score that considers many factors including water table depth and soil composition. Colorado’s Best Management Practices for controlling agricultural nitrate contamination are based on the Four R’s (Right rate, Right source, Right time and Right place).

Aside from legislative action, growers are being concerned over their own wells and soil health. One measure that growers can take to monitor and prevent soil leaching in their own fields is precision irrigation management.

Precision irrigation management

Controlling the timing and amount of irrigation water applied during the growing cycle can prevent irrigation water from leaching, that is, seeping down through the vados zone into the water table, as the available water is completely taken up by the plants. Successful management to prevent soil leaching depends on knowledge of root depth at any given time to ensure that roots receive water, but leachate is controlled.

Precision irrigation management is essential for maintaining the right amount of moisture at the crop’s roots, in addition to monitoring salinity and soil temperature. Correct irrigation management combined with appropriate regenerative practices can produce long-term benefits for soil health. Learn more here.

Monitoring root depth and water uptake with AquaSpy® Crophesy™ Soil Intelligence

AquaSpy’s unique layer by layer view into the soil and the crop’s active root zone gives growers detailed insight into how far each irrigation is reaching with relationship to the crop’s roots. Since soil leaching takes place when irrigation pushes nutrients below the roots where it can’t be readily consumed by the crop, this wastes fertilizer as well as leaving it deep in the soil layers where it can accumulate and/or seep further into the ground water table.

AquaSpy’s Fuel Gauge shows growers exactly where crops roots are so that:

• They can precisely time fertilizer applications
• They can precisely control irrigation amounts so as to provide as much water as the crop can consume

Conclusion

Agricultural states are seeing the amounts of nitrate in groundwater push past EPA approved levels, largely because of soil leaching from overuse of nitrogen fertilizers. Most of these states have programs in place to monitor nitrogen by sampling well water and other sources. Monitoring and Best Management Practices programs have been put into place, mostly voluntary because growers care about the safety of the water they drink.

Regenerative farming may have answers, as these programs advocate no-till, minimal fertilizer and cover cropping to pull out excess nitrogen and encourage microbial growth to supply nitrogen the plants need naturally. Paired with consistent sensor-based precision irrigation management, regenerative practices may be the best answer to prevent soil leaching for the future.

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