Mulching for soil quality, climate stress mitigation and crop productivity in okra

Abstract

Global warming and climate change is the greatest concern of mankind in 21st century. Under changing climatic scenarios crop failures, reduction in yields, reduction in quality and increasing pest and disease problems are common and they render the vegetable cultivation unprofitable. Various crop management practices such as mulching and the use of shelters and raised beds help to conserve soil moisture, prevent soil degradation, and protect vegetables from heavy rains, high temperatures and flooding. These protective coverings reduce evaporation, moderate the soil temperature and reduce soil run-off and erosion. A study entitled “Mulching for soil quality, climate stress mitigation and crop productivity in okra” was carried out at the Academy of Climate Change Education and Research, Kerala Agricultural University, Vellanikkara, Thrissur during 2015-2016. The experiment consisted of 9 treatments. Mulching with leaf litter, paddy straw, coir pith, black and white embossed sheet, black and silver embossed sheet, newspaper, coir chips, un mulched control and live mulch (cow pea). The biometric and phenological parameters were significantly influenced by the treatments. The plots mulched with plastic sheets showed early germination and higher germination percentage. The highest plant height and maximum number of leaves recorded were in plots mulched with black and silver embossed sheet. Plants mulched with paddy straw flowered earlier (38.33 DAS) and the highest number of flowers (25.66) was recorded in plots mulched with black and silver embossed sheet. In general, mulching with plastic sheets promoted early harvesting and highest crop duration. The highest yield (14.41 t/ha) was observed in plots mulched with black and silver embossed sheet. The soil microbial count was significantly influenced by the treatments. The highest population of bacteria (52.33 × 106cfu g-1) and actinomycetes (171.00 × 105cfu g-1) were observed in plots mulched with paddy straw whereas, the highest population of fungi (22.67 × 104cfu g-1) was observed in plots mulched with leaf litter. With regard to the soil microclimate, the peak value of minimum soil temperature at different depths was recorded in the plots mulched with plastic sheets. The peak value of maximum soil temperature at different depths is observed under plots mulched with black and silver embossed sheet followed by mulching with newspaper. The lowest value of maximum soil temperature at different depth was observed under plots mulched with paddy straw (T2). Higher soil moisture content was recorded under plots mulched with paddy straw throughout the crop period. Plots mulched with coir pith and coir chips also maintained higher moisture content at surface. The results of the present study revealed that mulching has significant influence on soil physical, chemical and biological properties. Mulching with black and silver embossed sheet maintained the soil microclimate which inturn helped to improve the growth and yield of okra.