Soil Fertility, Erosion, Runoff and Crop Productivity Affected by Different Farming Systems

A field study was undertaken with four farming systems (FS) such as; grasses and fodders, agro-forestry, agriculture (new farming systems) and shifting cultivation (old practice), to investigate the effect of land use on the soil properties, erosion and crop productivity on a loamy acidic Alfisol. Besides crops, the livestock were also kept and their dropping were incorporated in the respective watersheds. Soil sampling was done during first week of May every year from ۰-۲۰ cm depth, with auger. A significant increase in soil organic carbon (SOC) up to ۰.۹۹%, available P up to ۱۷.۲ mg kg-۱, K up to ۱۷۰ mg kg-۱ of soil, pH up to ۶.۳, was found after ۱۰ years of study over their initial values of ۰.۴۶%, ۲.۷ kg-۱, ۱۰۵ kg-۱ of soil and ۴.۹, respectively, in the new FS. In shifting cultivation, K status increased up to three years of study and then subsequently decreased. Diethylen etriamine penta acetic acid (DTPA) extractable Zn, Mn, Fe and Cu decreased in all the farming systems. Exchangeable Al content decreased from ۱۱۷ to ۳۷ mg kg-۱ of soil, in new FS. The study showed that about ۹۱.۱% to ۹۹.۱% rainwater could be retained depending on the vegetation cover in new FS, as against ۶۶.۳% in the shifting cultivation. New FS ameliorated the soil by decreasing exchangeable Al and Fe and enhancing soil pH. Soil and nutrient losses were significantly less and crop productivity higher in new FS compared to shifting cultivation.

کلیدواژه ها:

Farming systems ، Shifting cultivation ، Soil erosion ، Soil fertility