Agriculture Reference
In-Depth Information
12.2.1
Mulching
The effects of crop residues on soil productivity and as surface mulches are quite
promising. To define it more precisely this is a simple method for recycling of crop
residues if incorporation of organic matter in the soil or composting be applied. Sev-
eral scientist perform experiments and have reported that straw mulches are helpful
in conserving soil moisture, thereby saving irrigation, control of weeds and eventu-
ally increases the crop yield (Gaur
1986
). Mukharjee and Gaur (
1984
) reported that
various mulched treatments increased the ammonical and nitrate nitrogen, available
phosphorus, humus content and microbial population over unmulched control. Pad-
dy-straw as soil mulched significantly increased the grain yields of different crops
such as wheat, pea, green gram and maize over unmulched treatment (Gaur
1978
;
Gaur and Mukharjee
1980
). Mukharjee and Guar (
1984
) further reported that ap-
plication of FYM and as amendments in soil under mulched condition increased the
grain yield because of increase in ammonical and nitrate nitrogen, available phos-
phorus and humus content of soil and crop yield. Several recent scientific contribu-
tions standardize the effectiveness and importance of mulching in soil recycling
(Fan et al.
2005
; Li et al.
2006
; Adekalu et al.
2007
; Huang et al.
2008
; Bezborodov
et al.
2010
; Li et al.
2012
).
Decomposition of nutrients released from mulch with five different leguminous
species confirmed that low quality and high amount of organic C as mulch applica-
tion act as limiting factor for the quantity of energy available for microorganisms
and increases the nutrient immobilization for biomass decomposition, which results
in competition for nutrients to the crop plants (Cattanio et al.
2008
). Recent re-
search by Silverman et al. (
2006
) have shown that mulching significantly increased
available water capacity by 18-35 %, total porosity by 35-46 % and soil moisture
retention at low suctions from 29 to 70 %. At high suctions, no differences in soil
moisture content were observed between mulch levels. Soil bulk density was not af-
fected by mulch rate. High correlations obtained between mulch rate and soil mean
weight diameter (R
2
= 0.87) and percent stable aggregates (R
2
= 0.84). Mulching the
soil surface with a layer of plant residue is an effective method of conserving water
and soil because it reduces surface runoff, increases infiltration of water into the
soil and retard soil erosion. The effectiveness of using elephant grass (
Pennisetum
purpureum
) as mulching material facilitates runoff and soil loss decreased with the
amount of mulch used and increased with slope. Mulching the soils with elephant
grass residue may benefit late cropping (second cropping) by increasing stored soil
water for use during dry weather and help to reduce erosion on sloping land (Xia
et al.
2013
).
12.2.2
Composting
Composting is one of the oldest solid waste treatment methods known to man
since Biblical or Vedic period. The scientific study of composting was initiated by
