Measuring irrigation distribution is important and especially effective when used in combination with practices that support a healthy soil.
The moisture content of the soil regulates the moisture levels in the plant. Overly dry or overly moist soil stresses the plant and can induce diseases and reduce future seasons’ yields. This is why it is important to monitor soil moisture in order to schedule irrigation and provide the crop with adequate water to achieve ideal growth and yields.
Soil moisture-monitoring devices use sensors and probes located in the soil root zone. Combined with information about temperature, vapotranspiration (evaporation from the soil and transpiration from the plant), and water requirements of the crop, these devices are able to provide the farmer with information that can be used to schedule irrigation properly.
Another important component in managing soil moisture is irrigation distribution uniformity. This measures how evenly water is applied to a crop across a field during irrigation. Microsprinklers often get plugged, as do drip emitters.
Sprinkler heads get worn, and leaks in the system affect distribution uniformity, not to mention human error (a worker forgot to turn a valve, etc.). All these can significantly affect water distribution, and fertiliser distribution if the farmer is fertigating. If water distribution is uneven in a field, it will negatively affect yields. Inspecting and performing distribution evaluation in your
irrigation system will identify the causes, and corrections can be made to eliminate plugging, minimise variation in pressure, and adjust flow rate, infiltration time, spacing, set duration, and land grading.
Strategies to reduce crop water use:
• Maintain healthy, water-absorbent soils
• Match plant genetics – varieties, growth characteristics, and tolerances (heat, salinity, pests, drought, early maturing etc.) – to specific conditions
• Replace high-water-consuming crops with water-efficient crops
• Implement cultural practices: conservation tillage, planting densities, double cropping, intercropping, and crop rotation
• Improve irrigation timing through scientific irrigation scheduling, a systematic procedure that calculates precise water requirements over a short period of time to meet crop needs
• Manage deficit irrigations
• Use irrigation technology: sensor devices, probes, computer technology
• Utilise low-volume irrigation systems: drip irrigation and micro sprinklers, surge, and sprinklers
• Irrigate at night
• Practice weed control
• Apply mulches
• Reduce tillage.
Farmers across the country are operating in an era of uncertain weather and uncertain markets. Many farmers have reduced their input costs and increased their bottom lines by choosing to invest in soil health, just as they would in new machinery and maintaining farm structures.
Healthy, living soils can better sustain the increased demands we’re placing on them to grow healthy food and maintain clean water and air. It is important to build and maintain soil health before drought or flood conditions appear. Healthy soils can better withstand climatic stresses of drought and floods and, in some cases, can help mitigate these stresses.
All this requires an increased understanding about how to manage the soil as an ecology. Investments, such as adding organic amendments, practicing no- or reduced tillage, leaving crop residue, planting cover crops, and diverse crop rotations, will help the soil efficiently cycle both water and nutrients, sustain plant and animal productivity, and maintain or improve water quality. The return on soil health investments will pay off year after year after year.
Source: ATTRA Sustainable Agriculture – NCAT
