Agricultural Systems of the Northeastern Hill Region of India

Sustainability of sloping land cultivation systems in the mid‐hills of Nepal

“…Farmers have learned to adjust their land use practices to accommodate the effects of erosion by, for example planting different crops in zones of net loss and net deposition (van Noordwijk et al, 1998), so that expensive technologies that minimise such transfer by surface runoff and erosion may not actually address farmers' needs. Ramakrishnan (1990) was also rightly concerned that, on long-hillslopes, minimisation of surface runoff, by increasing infiltration, may not be advantageous to overall soil fertility and agricultural productivity, because of increased nutrient losses through leaching. Therefore, the objectives of studies need to be carefully framed to distinguish net impacts of changes in land use at the individual plot scale, at the whole hillslope scale or on the rate of discharge into rivers at the bottom of the hillslope; and need to take into account the complexities of spatial linkages and transfers across and down whole hillslopes (Gardner and Gerrard, 2003).…”

Improved agroforestry systems for steeplands in the Caribbean.

“…by planting different crops in zones of net loss and net deposition (van Noordwijk et al, 1998)), so expensive technologies that minimize such transfer by surface runoff and erosion may not actually meet farmer's needs. Ramakrishnan (1990) was also concerned that, on long-hillslopes, minimization of surface runoff (by increasing infiltration) may not be advantageous to overall soil fertility and agricultural productivity. Therefore, the objectives of studies need to be carefully framed to distinguish net impacts of changes in land use at the individual plot scale, at the whole hillslope scale, or at the bottom of the hillslope (rate of discharge into rivers).…”

“…On gently sloping land with an acid soil in the Philippines Samsuzzaman et al (1999) found that three year-old hedgerows made no significant difference to the rate of decline in soil organic C, total N, available P concentrations or pH values. Young (1989) proposed that there were three main mechanisms by which contour hedgerows can affect soil properties: increasing water infiltration (which reduces runoff, but can increase nutrient losses through leaching (Ramakrishnan, 1990)); acting as a sieve barrier to eroding soil; and increasing OM inputs to the soil through the addition of hedgerow prunings as a mulch (which may also serve to increase the rate of nutrient cycling). In our study the addition of hedgerow prunings may have had an effect: from 1995 annual input from the prunings to the soil of OM was equivalent to c. 10.8% of the standing stock present in the < 2 mm diameter mineral and litter fractions combined in the top 10 cm of soil between the hedgerows, for total N it was c. 16.8% but for total P only 3.3%.…”