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United States Department of Agriculture

Agricultural Research Service

Research Project: Improving Irrigation Management for Humid and Sub-Humid Climates

Location: Cropping Systems and Water Quality Research

2012 Annual Report


1a.Objectives (from AD-416):
Objective 1: Evaluate and optimize production systems for irrigated cotton, corn, and rice to optimize WUE under variable weather conditions that are expected to become more variable with impacts of climate change while considering the constraints of timing for field operations, a limited growing season, and increasingly limited water supplies. 1a: Determine crop coefficient for sprinkler irrigated rice. 1b: Determine water/yield relationships for sprinkler-irrigated rice and cotton. 1c: Compare drought-tolerant corn hybrids to those currently grown. 1d: Develop database of water use variation among rice production systems. Objective 2: Evaluate the suitability of variable-rate center pivot irrigation for crop production on variable soils and in varying weather conditions to determine potential costs and benefits for producers. 2a: Determine the utility of soil apparent electrical conductivity (ECa) and topographic variables for defining management zones to develop prescriptions for VRI management. 2b: Determine the optimum irrigation schedule for rice under center pivot irrigation over a range of sand contents. Objective 3: Evaluate the quality of runoff from irrigated cropland to determine current and potential environmental risks and develop guidelines and BMPs to reduce impact of irrigated agriculture on water quality degradation. 3a: Determine nutrient content of runoff from surface drained land in the lower Mississippi River basin. 3b: Develop guidelines for fertigation for center pivots in humid and sub-humid regions. 3c: Determine greenhouse gas (GHG) emissions associated with different water management strategies for rice production and options for reducing. 3d: Develop a variable source N application system utilizing controlled release nitrogen (CRN) technology to reduce N losses in furrow irrigated cotton.


1b.Approach (from AD-416):
Evaluate and optimize production systems for irrigated cotton, corn, and rice to optimize WUE under variable weather conditions that are expected to become more variable with impacts of climate change while considering the constraints of timing for field operations, a limited growing season, and increasingly limited water supplies. Evaluate the suitability of variable-rate center pivot irrigation for crop production on variable soils and in varying weather conditions to determine potential costs and benefits for producers. Evaluate the quality of runoff from irrigated cropland to determine current and potential environmental risks and develop guidelines and BMPs to reduce impact of irrigated agriculture on water quality degradation.


3.Progress Report:
This report documents progress for Project Number 3622-13610-003-00D, which started in April 2012 and includes objectives from both Agricultural Research Service (ARS) and University of Missouri scientists. It continues research from Project Number 3622-12610-002-00D, entitled “Optimizing Irrigation Management for Humid Climates.” During FY12 progress has begun on all objectives of the new project. Under ARS leadership: (1) Initiated study comparing standard and drought-tolerant corn hybrids. Modified adjustable mobile sensor system used to measure spatially referenced canopy temperature, reflectance, and height, and temperature and relative humidity of air above the crop with additional reflectance sensors for inter-row measurements. The new system was tested in corn and cotton studies. Established a corn/cotton rotation in field precision graded in 2011. Harvest yield monitor data will be analyzed to investigate continuing effects from land grading. (2) Installed variable rate irrigation (VRI) systems to allow more treatments in cotton, soybean, and rice irrigation studies. (3) Maintained samplers and collected continuous stage and flow information from three southeast Missouri sites and conducted monthly runoff sampling for water quality determination. Through specific cooperative agreement with the University of Missouri (see also 3622-13610-003-01S, Improving Irrigation Management and Irrigated Crop Production in Southeast Missouri): (1) A 152 meter center pivot irrigation system was adapted to allow VRI application, with ten independent zones of approximately equal area. A 113 meter center pivot system was also adapted to allow VRI application, with independent control of each of 48 nozzles. Rice studies were conducted under both systems, as well as cotton and soybean. A 156 m center pivot system equipped with seven equal-area zones along the pivot lateral was studied to evaluate application uniformity, confirm nozzle pulsing rates used to achieve variable application, and evaluate timing influence on application uniformity. (2) Cotton measurements of spatially referenced canopy temperature, reflectance, and height, and temperature and relative humidity of air above the crop were continued in two ongoing studies. (3) Rice yield response has been evaluated with biochar applications under different water management practices. (4) Three soil types and four insecticides were tested. Water samples were collected after flooding was established. (5) On-farm studies were conducted to evaluate the effectiveness of controlled release nitrogen (CRN) fertilizers relative to traditional nitrogen fertilizer programs for furrow irrigated cotton production. (6) Corn fertigation and soybean fungicide chemigation studies were initiated.


Last Modified: 9/20/2014
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