Impact of different cropping systems on properties of soil and water in different micro watersheds

Abstract

Studies on soils of Navsari Agricultural University (NAU) having different cropping system were carried out in the four micro watersheds that exist in the 400 ha University campus. Soil samples from 0-15 cm depth and water samples from adjacent bore wells were collected and analyzed from different locations of micro watersheds. Soils of watersheds showed that soils texture was clay in nature, having more than 65 % clay, whereas silt was more in watershed ‘A’. Soil organic carbon content (SOC) was 0.32 %, found in the field near University play ground and the highest 0.88 %, in Forestry farm, thus underlining the need of forest species in agricultural farms. SOC levels have reduced significantly due to intensive cultivation in all the watersheds. The result of exchangeable sodium percent (ESP) is supported by the topographic features, as, ESP was more in watershed ‘B’ (5.15) than C (2.95), this showed that infiltration rate was lesser in ‘B’ as compared to ‘C’ due to availability of more sodium (Na). Available N was highest in watershed ‘A’ (246 kg/ha) followed by ‘C’ (225 kg/ha) than ‘B’ (203 kg/ha), the reason was watershed ‘A’ had only horticulture crops whereas B and C had different crops of the region. Electrical conductivity (EC) of ground water collected from wells in watershed ‘C’ was found to be very high both before (3.44 dS/m) and after monsoon (2.95 dS/m), showing that water is highly saline and not fit for surface irrigation and there is need of ground water recharging.