Assessing Soil Chemical and Biological Properties under Major Cropping Systems in SPSR Nellore District, Andhra Pradesh, India

A study was carried out during 2023-24 in SPSR Nellore district of Andhra Pradesh, India to know the impact of major cropping systems on soil chemical and biological properties. Totally 100 soil samples were collected randomly from five major cropping systems viz., paddy-paddy, fallow-paddy, paddy-cotton, paddy-pulses and groundnut-paddy (20 samples from each cropping systems) in SPSR Nellore district and processed, analyzed for available nitrogen, phosphorus, potassium and sulphur and dehydrogenase enzyme. The results revealed that available nitrogen in soils varied from 88 kg ha-1 in paddy-cotton cropping system to 289 kg ha-1 in paddy-pulses cropping system with a mean value of 130 and 242 kg ha-1 respectively. 95% of samples showed deficient in available nitrogen. The available phosphorous in soils varied from 19 kg ha-1 in paddy-cotton cropping system to 58 kg ha-1 in paddy-pulses cropping system. The mean available phosphorus is 37.03 and 42.8 kg ha-1 respectively. The available potassium in soils varied from 177 kg ha-1 in paddy-paddy cropping system to 601 kg ha-1 in paddy-pulses cropping system. The available potassium of soils of different cropping systems was medium to high in range. The available sulphur of soils varied from 7.56 mg kg-1 in paddy-paddy cropping system to 33.73 mg kg-1 in paddy-pulses cropping system. The soils had deficient to sufficient in available sulphur in various cropping systems at SPSR Nellore district of Andhra Pradesh. The soils in paddy-pulses cropping system showed the highest dehydrogenase activity (116.47 µg of TPF g-1 soil day-1) whereas the lowest dehydrogenase activity (18.08 µg of TPF g-1day-1) was observed in paddy-paddy cropping system.