Effect of Winter Wheat Crop Residue on No‐Till Corn Growth and Development

Abstract

Two established methods for increasing the sustainability of production agricultural cropping systems are (i) increasing crop residue levels by reducing tillage and (ii) including a winter annual crop in the rotation. A wide range of crop yield responses have been reported for no‐till systems adopted to a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation. However, little research has been done in the Northern Corn Belt on no‐till corn following winter wheat (Triticum aestivum L.). The objective of this study was to evaluate the effect of winter wheat crop residue on the growth and development of no‐till corn. The experimental design was a randomized complete block. Treatments consisted of no‐till systems with three levels of winter wheat residue [no wheat residue (NWR), wheat root residue only (WRR), and wheat root and shoot residue (WRSR)]. Data were collected in 2003, 2004, and 2005. Measurements included plant emergence, plant height, time of tasseling (VT stage), chlorophyll content, presidedress soil nitrate test (PSNT) soil nitrate levels, soil moisture and temperature, corn grain yield, grain moisture, and grain test weight of corn at harvest. In all years, the presence of winter wheat residue above and below ground decreased soil temperature, increased soil moisture, and decreased chlorophyll content in corn leaves and plant height in the early stages of corn development. The VT stage of corn was delayed for about 1 wk in residue systems. Winter wheat residue decreased the amount of plant available N and increased grain moisture and test weight of corn grain at harvest. Emergence and population of corn in 2003 and 2005 were reduced in residue systems. The use of a PSNT‐based N application rate was successful in maintaining corn grain yield in wheat residue systems with corn grain yield in NWR systems in 2003 and 2004 despite wheat residue antagonism of corn growth and development. In 2005, corn grain yield in wheat residue treatments was less than in NWR treatments, but was equal to PSNT target yields.