BSc-MSc (Integrated)

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.