Effect of soil management on rain-fed wheat in Northern India. I. Hydro-thermal regime and root growth

Abstract

Field experiments were conducted on a silty clay loam soil during 1980–1981 and 1981–1982 to study the effect of different soil management practices, such as zero cultivation (ZC), conventional cultivation (CC), CC + surface-applied pine needle mulch at a rate of 10 t ha −1 (CC + M), deep ploughing (DP) and inter-row compaction (IRC), on the soil hydro-thermal regime and root growth of wheat ( Triticum aestivum L.). The soil of the experimental site is classified as Alfisol, Typic Hapludalf in which compact sub-surface layers are encountered. In the CC + M treatment, the soil water potential in the sub-surface layers remained higher in comparison to other treatments. In the DP treatment, the decrease in soil water potential was observed to greater depths in comparison to the remaining treatments. The soil water flux at 60-cm depth, calculated during 150–173 days of crop growth, was always upward in the CC + M treatment, at a rate varying from 0.2 to 1.16 cm day −1. In the other treatments, the flux at this depth was first downward then it became upward. The upward flux was highest under the DP treatment, followed by CC and CC + M and least under IRC and ZC treatments. The minimum temperature under CC + M treatment at 10-cm depth was raised by 4°C over the temperature under CC treatment (5°C). The rooting density and length in the CC + M treatment were the highest, followed by DP treatment, in comparison to the remaining treatments.