Manure Application in Strip Tillage: Effects on Grain Sorghum Yield, Water Use Efficiency, and Nutrient Uptake Under Dryland Cropping Systems.

Minimizing the input cost and maximizing the resource efficiency are crucial for the success of any dryland cropping systems in semi-arid environments of southern Great Plains. Manure has long been proven to be an excellent source of organic matter and plant nutrients. However, the excessive application of manure to agricultural lands may often lead to potential excessive nitrate and salt accumulation, undesirable microbial load and pathogens, greenhouse gas emissions, and eutrophication problems. Moreover, the costs associated with manure material, application, and handling can substantially affect the input cost of dryland cropping systems. In view of importance of optimal use of manure, a study was conducted in 2015-2017 at Tucumcari, NM to evaluate the manure rate (12 and 24 ton ha^-1) and incorporation (surface and incorporated at 15 cm) effects on water dynamics, nutrient availability, and yield characteristics of grain sorghum in strip tillage systems under dryland conditions. Results in 2015 and 2016 suggested that higher manure rate (24 t ha^-1) and incorporation at 15 cm maximized Nitrate-N and Olsen P concentrations, grain and biomass yield, and grain water use efficiency. The experiment for 2017 is in progress at the time of this submission. Details about more results will follow.