Peanut is a relatively drought-sensitive and salinity-sensitive crop. Water management and environmental conditions are very important factors in quality (maturity, flavor and risk of aflatoxin development) and ultimately to the marketability of peanuts. Therefore, care should be taken to avoid excessive drought stress of the crop.
- Increase understanding of water requirements (peak water use, seasonal water use, critical growth stages, drought sensitivity/tolerance, and water quality requirements) of peanuts.
- Increase water use efficiency and profitability in peanut production through application of appropriate best management practices.
- Key Points:
- Peanut is relatively sensitive to drought and salinity. Peanut has a relatively limited rooting depth (generally 3 ft. or less), and coarse soils (well suited to peanut harvest) generally have low water storage capacity. Therefore irrigation management is very important in peanut production.
- Seasonal water use for peanut in Texas is approximately 20 to 30 inches per season from rainfall, irrigation and limited soil moisture. Seasonal water demand in the Texas Southern High Plains is approximately 28-30 inches.
- Peak water use occurs during pegging and pod development. During this time crop water demand can be 0.3 to 0.4 inches per day (depending upon location and weather conditions).
- Near-surface soil moisture is important during and after pegging to facilitate peg penetration into the soil and pod development.
- Assess your knowledge:
- What is the peak water use of peanut in you area? When (growth stage and calendar range) does this occur?
- What is the maximum effective root zone depth for peanut? Are there other factors in your field or management program that you would expect to limit this effective root zone depth? What practical significance do these limitations have with respect to your irrigation and nutrient management programs?
- Are there water quality (salinity) concerns for peanut production on your farm? If so, what are they? How can they be managed?
- What irrigation method do you currently use to irrigate peanut? What best management practices (BMPs) are you using to optimize water use efficiency? Identify other methods and BMPs that would be applicable to your operation.
- Plan ahead to meet irrigation requirements
Consider your irrigation capacity and plant what your system can reasonably support. Peak water use can be 1/3 inch per day, and coarse soils have little water holding capacity. Become familiar with the crop water use by growth stage.
Maintain irrigation equipment
Maintain your irrigation equipment to avoid costly down time and application inefficiency. Monitor system pressure and flow. Check sprinkler or LEPA nozzle packages to maximize water distribution uniformity. Consider using pressure regulators on center pivot or linear irrigation systems applying to sloping fields.
Manage irrigation efficiently
Roots grow in moist soil. Effective root zone for peanut is generally approximately 3 ft. in depth, unless otherwise limited by a caliche layer, dry soil, or other barriers. Use knowledge of soil water holding capacity and soil moisture monitoring to plan irrigation applications. Frequent light irrigation applications may result in excessive evaporation losses. Irrigation applications that exceed the soil’s water holding capacity can result in runoff losses and/or deep percolation losses. In-season soil moisture monitoring is key to optimizing irrigation management.
Check for salinity
Peanut is a relatively salt sensitive crop. Have a water sample analyzed for salinity (electrical conductivity, “EC”, or total dissolved solids, “TDS”), boron, chloride, and sodium. Include salinity analysis in your soil testing. Mitigate salt accumulation, if necessary. In some cases, LEPA or furrow irrigation can reduce foliar salt damage. In some instances, salinity or concentrations of specific elements (such as boron) may be too high for peanut production.
Manage irrigation for root zone, as well as for pegging and pod development
Peanut root zone soil moisture supports the plant’s water needs. Near-surface soil moisture is necessary to allow peg penetration into the soil and pod development.
Information compiled by Dr. Dana Porter, TCE/TAES agricultural engineer and Dr. Mike Schubert, TAES peanut agronomist, Texas A&M AgriLife Research and Extension Center, Lubbock, TX.