Ag FIELD ASSESSMENT FOR EVALUATING ALTERNATIVE *BMPs

Soil Stratification: clay lens; impermeable layers; root zone depth; water holding capacity; plant extraction patterns; etc.

Crop: variety; expected yield; crop quality; crop history (cultural practices, inputs, operational costs); water quality and availability; crop salt tolerance; crop nutrient requirements; etc.

Typical parameters analyzed and/or observed include: Soil texture; Soil structure; Soil tilth; Soil salinity; Exchangeable Sodium Percent; Soil organic matter (i.e., based on crop rotations, cultivation practices, and residue management); Irrigation water quality (Total Dissolved Solids, pH, Sodium Adsorption Ratio, Alkalinity); Soil surface sealing (with hard surface crust when dry); stunted plant growth (e.g., chlorotic leaves; defoliation; wilted plants; deformed plant growth; Disease, Insect, and Weed problems); depth to water table; Drain condition and maintenance; Canal seepage losses; Excessive cultivation; Water stress (e.g., water-logged soils); Comprehensive nutrient management (nutrient budget; macro and/or micro nutrient deficiency, toxicity, and imbalance); Irrigation Water Management (e.g., irrigation efficiency and uniformity; irrigation system constraints); Energy requirements (fuel, electricity); etc.

Typical Best Management Practices implemented: Irrigation water management (concrete-lined ditches, laser leveled fields, water metering, high flow turnouts, irrigation scheduling, drain maintenance, remote sensing with near infrared analysis, leaching requirement); Nutrient management (develop a nutrient budget): Split-application of nitrogen fertilizer (i.e., based on type, rate, method of application, cost, chemical reaction, and placement) and Foliar spray; comprehensive soil, leaf/petiole, water, and animal waste analysis; Judicious use of soil amendments: elemental sulfur, gypsum, polyacrylamide, manure, sulfuric acid, and compost; Cultivation practices: e.g., mowing program for orchards, chiseling, crop rotations; Integrated pest management: pest identification (i.e., pest scouting) and proper pesticide selection, use of biological controls; Integrated weed management: weed identification, proper herbicide selection, and cultivation practices.

The Mesilla Valley Precision Farming Pilot Project is employing Aerial Photography (Remote sensing/near infrared analysis), Geographic Information System, and Global Positioning System Technologies, which are being used in conjunction with the Holistic Irrigation Technology Program developed by the USDA-NRCS Staff in Las Cruces, New Mexico. These technologies will be used for developing and analyzing vegetation stress maps that will relate multiple field parameters to specific soil types and management practices (i.e., through extensive field data collection of the following items: soil, plant-petiole, and water analysis; fertilizer, pesticide, herbicide, soil amendments, and other inputs; cultural practices; weather conditions; irrigation water management; yield and crop quality; and other pertinent information). This analysis of site-specific field conditions should lead to the development of predictable and useful information (e.g., the understanding of patterns, trends, correlations, soil indexes, etc. that are related to optimal crop productivity); this will increase our understanding on how to more effectively and efficiently make sound and sustainable agricultural decisions.