Vol. 10, Issue 10 (2021)

Author(s):
Suraj Mali and GH Santra

Abstract:
Low grade Rock phosphate (RP) was supplied by FCI Aravali Gypsum and Minerals India ltd. A field experiment was conducted with maize-groundnut cropping sequence. Rock phosphate and its combination with SSP were used as nutrient sources during Rabi 2016-17 (maize taken up in Kharif 2016). The study was carried out in the Central Farm, OUAT with the help of a field experiment laid out in Randomized Block Design with seven treatment T₁ - Control, T₂ - 100% P(RP), T₃ - 100% P(SSP), T₄ - 75% P(RP) + 25% P(SSP), T₅ - 50% P(RP) + 50% P(SSP), T₆ - 25% P(RP) + 75% P(SSP) and T₇ - 100% P(SSP) + Lime @ 0.2 LR and replicated in thrice. The soil of the experimental field was loamy acidic (pH 5.2) having Bray’s P of 15.68 kg ha^-1. The different combinations with SSP were evaluated for their effectiveness in the cropping system. In addition to P applied @50kg P₂O₅ ha^-1 and 40 kg P₂O₅ ha^-1 to maize and groundnut crops respectively from various sources, N was added @ 150kg ha^-1 to maize and 20 kg ha^-1 to groundnut crop in the form of urea and K @50 and 40 kg K₂O ha^-1 was added to maize and groundnut crop in the form of MOP. The results of present investigation were obtained that the harvest of the crop the soil exhibited a marginal increase or decrease in the available N level. 100% P (SSP) + Lime @ 0.2 LR exhibited the maximum available N throughout the growth period of groundnut. The treatment 100% P (SSP) + Lime@ 0.2 L.R produced maximum soil available P during flowering and harvesting stages (33.7 and 27.7 kg P₂O₅ ha^-1). This level of potassium slightly decreased towards the harvest of the crop. The maximum available S was obtained with 100% P (SSP) + Lime@ 0.2 LR followed by 100% P (SSP) at all stages of growth. Control had the lowest available S during the period of all growth stages. The treatment received 75% P (RP) +25% P (SSP) produced maximum and the minimum available Ca in control plot at all growth stages.