Effect of straw mulching, irrigation and fertilizer nitrogen levels on soil hydrothermal regime, water use and yield of hybrid chilli

Abstract

In northern India, chilli is transplanted in the hot and dry months of February and March when the crop depends upon irrigation water for canopy establishment. Hybrid chilli may require more irrigation water and fertilizer N due to its higher yield potential but the problem of the depleting groundwater table in the region necessitates developing a technique for reducing water requirement. Rice residue mulching can lower soil temperature and reduce evaporation losses from soil. An experiment was conducted on sandy loam soil for three years to evaluate the effect of rice straw mulch @ 6 Mg ha⁻¹ on yield, fertilizer N and irrigation water requirement of hybrid chilli. Maximum and minimum soil temperatures at 50 mm depth during 2003 were lowered up to 8.9 and 2.2°C, respectively, by rice residue mulching. Mulching improved fresh red chilli yield by 2.4 Mg ha⁻¹ and required 120 mm less irrigation water. Substantial yield increase with mulching may be attributed to favourable soil hydrothermal regime as evident from lower soil temperature, higher profile moisture (12 mm) and 13.5 Mg ha⁻¹ lower weed biomass. Chilli yield obtained with 45 kg N ha⁻¹ with mulch was the same as that of 75 kg N ha⁻¹ without mulch. Ascorbic acid content decreased with lower irrigation frequency but was significantly higher without mulch.

Keywords:

• straw mulch
• irrigation
• fertilizer N
• soil temperature
• chilli yield