Agriculture Reference
In-Depth Information
In Pakistan, Iqbal et al. (2007) observed that minimum tillage, in conjunction with
FYM amendments, led to an increase in soil nutrient (N, P, and K) and organic matter
status, as well as maize yields. Another study in China showed that the conservation
tillage system involving ridges and furrows with seasonal no-till led to restoration of
physical, chemical, and biological properties of a degraded southern hill region soil
(Zhu et al. 2002). Such permanent bed or ridge and furrow planting systems have been
shown to have potential in the hill regions of Nepal, particularly for high-value crops
such as potato and other vegetables (Bajracharya 2001; Sherchan and Karki 2006).
6.4.5 B
Iogas
and
B
IoChar
Biogas slurry applied as a fertilizer and soil amendment has numerous beneficial effects
on the soil, as well as enhances yields. As >120,000 biogas plants have been installed in
rural areas across Nepal, it could serve as an important component of sustainable farm-
ing systems while simultaneously helping conserve forests and reduce carbon dioxide
and methane emissions to the atmosphere. Biogas slurry application was observed to
increase the yields of maize, rice, wheat, and cabbage by 30%, 23%, 16%, and 25%,
respectively, over the conventional farmer practice in the Nepal mid-hills (Karki 2004).
Biochar is a subject of recent scientific investigation as a potential means of
enhancing the carbon storage capacity and longevity in soils, while simultaneously
increasing the soils' fertility and productive capacity. Biochar, a pyrolysis product of
biomass, has been used by ancient civilizations in the Amazon, northwest Europe,
and the Andes (Sombroek et al. 1993; Sandor and Eash 1995; Downie et al. 2011). It
has recently gained scientific attention as a simple yet potentially powerful tool for
climate change mitigation while contributing to sustainable agricultural production
(Downie et al. 2011; International Biochar Initiative 2012). The benefits of biochar
reportedly result from its high stability, porosity, and resistance to microbial break-
down, thereby acting as sites for increased water and nutrient retention (Sohi 2012).
6.4.6 M
ICroIrrIgatIon
and
W
ater
M
anageMent
Water management will no doubt be a subject requiring considerable attention and
effort with climate change, erratic precipitation, and water scarcity becoming ever more
acute in the years to come. Yet, to meet the increasing demands and livelihood security,
farmers have opted to grow high-value and out-of-season vegetables such as tomatoes
(
Lycopersicon esculentum
Mill.), cucumber (
Cucumis sativus
L.), squash (
Cucurbita
pepo
L.), and cauliflower (
Brassica oleracea
L.). Such crops, however, are sensitive to
water stress and require a regular, reliable supply of water (Wan and Kang 2006; Enciso
et al. 2007). Under these conditions, drip or microirrigation offers a viable and water-
efficient option for irrigating vegetable crops during periods of water scarcity.
Drip or trickle irrigation is a type of microirrigation method intended for both
water conservation and efficient use of water by the crop. Microirrigation systems
deliver water in the form of drops, tiny streams, or miniature sprays directly to the
plant root zone. Such systems may be placed on the soil surface or at varying depths
in the crop bed (Schwab et al. 1993; Hla and Scherer 2003; Ensico et al. 2007).
Microirrigation systems have the advantage of enabling economic crop yields with
