Monday, November 13, 2006

The Interactions of Tillage and Crop Rotation on Soil Microclimate and Crop Performance.

Aaron Jeffries, Iowa State Univ, 1220 Marston Ave, Ames, IA 50010-5269 and Jerry L. Hatfield, National Soil Tilth Lab, 2150 Pammel Dr, Ames, IA 50011-4420.

Understanding the intricate interactions of management practices, soils, and plants is the beginning process towards the progression of agricultural systems that sustain food production. Microclimate is important in crop production because it impacts the adaptation of plant life from its diurnal course to annually.  Microclimate also influences the proficiency of crops to photosynthesize and produce the necessary compounds for growth, development, and reproduction. Corn (Zea mays L.) grown in annual rotation with soybean [Glycine max (L.) Merr.] has greater mineral nutrient accumulation in higher yields than corn grown in monoculture.  This study was conducted to determine the interaction of tillage (fall strip vs. spring strip) and crop rotation (continuous corn vs. corn rotated with soybean, soybean rotated with corn) on crop performance (yield, corn shoot weight, and mineral nutrition (C:N) throughout the growing season) and pre-growing season soil fertility (pH, organic matter, CEC, NO3-N, NH4-N, P, K, Ca, Mg, Na, and total N).  Crop rotation increased soil CEC, Ca, and Mg when compared with continuous corn. Crop rotation resulted in higher yield than continuous corn. Crop rotation increased corn shoot dry weight and height compared to continuous corn throughout the growing season. Soil water availability is often the main factor limiting crop production. In water-limiting systems, proficient acquisition and assimilation of precipitation is needed to maximize crop growth and yield.  In 2003 there was no significant difference between tillage systems and soil water content but there was a significant interaction between tillage and crop rotation on soil water content at the beginning of the growing season.