Influence of different agro-forestry land use systems on run-off, soil and nutrient losses in central dry zone of Karnataka.

摘要

A field experiment was conducted during 2002-03 and 2003-04 at the Zonal Agricultural Research Station, Hiriyur, Karnataka, India, to study and assess the effects of different agroforestry land use systems on runoff, soil erosion and nutrient losses. The results revealed that among the different land use systems in central dry zone (Hiriyur), recorded highest loss of organic matter (45.20 kg/ha), major nutrients (30.30 kg/ha), secondary nutrients (250.00 kg/ha) and micronutrients (8.5 kg/ha) were observed in silvi-horticulture system followed by agri-horti system, agri-system, silvi-hort-pasture system and the lowest was in natural system which recorded 13.00, 10.00, 85.80 and 3.10 kg/ha, respectively. The higher nutrient losses from silvi-horticulture system may be attributed to higher runoff soil losses from the system. This can be further explained by eroded material being rich in colloidal clay organic matter and plant nutrients. Since clay and organic matter act as sink and source of plant nutrients resulted in higher runoff and soil loss in silvi-horticultural system. However, highest amount of soil losses depends on soil properties, amount of runoff and ground cover in any land use system at Hiriyur. The highest amount of soil loss was recorded in silvi-hort system (2300.64 kg/ha) followed by agri-hort system (2250.60 kg/ha), agri-system (220.43 kg/ha), silvi-hort-pasture system (1200.20 kg/ha) and the lowest was with natural system (642.00 kg/ha)..