Effects of conservation tillage and nitrogen management on soil properties, crop productivity and nitrogen use efficiency of irrigated rice under North West India

Management practices that simultaneously improve soil properties and yield are crucial to sustain high crop production and minimize detrimental impact on the environment. The objective of this study was to determine the influence of tillage and crop nitrogen management on crop yield, N uptake and nutrient use efficiency. Rice is predominant in Typic Ustochrept soil of North West India. A two year field experiment was conducted to assess the effect of three tillage systems [conventional tillage (CT), furrow irrigated raised beds (FIRB) and reduced tillage (RT) and five rates of fertilizer N (0, 80, 120, 160 and 200kgNha-1) in rice crop was laid out in split plot design with three replication. Results indicated that the productivity of rice was significantly different in tillage systems. Response of fertilizer N was influenced by tillage systems, and crop response to fertilizer N was generally observed up to 160 kg N ha-1. Amount of N uptake in rice generally increased with N rate, but tillage had no consistent effect. An improvement in selected soil physical properties like bulk density, stable aggregate size classes, infiltration rate, electrical conductivity and soil penetration resistance was recorded in FIRB, and RT than in CT. The size distributions of aggregates were also significantly influenced by tillage practices. Small macro-aggregates comprised the greatest proportion of the whole soil, followed by aggregates 2 mm) in FIRB plots at depth of 0 to 10, 10 to 20, and 20 to 30 cm was approximately twice the percentage under CT but significant only below the 10-cm soil layer indicating less potential for soil erosion when tillage was omitted. It is concluded that furrow irrigated raised beds i.e. wide raised beds systems with 160 kg N ha-1 would be a suitable practice for sustainable production of rice crop in Typic Ustochrept soil of North West India.