Impact of STCR Based Nutrient Application on Dry Matter Accumulation, Partitioning of Potassium in Rice (Oryza sativa L.) and Potassium Fractions in Black Cotton Soil of Central India

Chemical fertilizers used by the majority of Indian farmers are based on a generalized recommendation that overlooks soil fertility and crop response. These broad recommendations frequently result in under- or over-fertilization, resulting in reduced productivity, efficiency, and environmental pollution. To address these issues, the STCR-target yield approach appears to be promising. However, the dynamics of potassium (K), an important primary essential nutrient, is not fully understood under STCR based approach. Therefore, our current study was aimed to profile the dynamics of potassium in rice parts and its different forms in vertisol. The present study was conducted at the soil science research farm of Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur, Madhya Pradesh, a part of AICRP on the effect of soil test and crop response based nutrient management on potassium partitioning in rice crop and its fractions in vertisol of Madhya Pradesh. The treatments comprised of T1 : Control (no fertilizer application); T2 : General recommended dose (120:60:40 N, P2O5 and K2O kg ha-1); T3 : Targeted Yield 50 q ha-1 (115:90:49 N, P2O5 and K2O kg ha-1); T4 : Targeted Yield 60 q ha-1 (157:125:70 N, P2O5 and K2O kg ha-1); T5 : Targeted Yield 50 q ha-1 with 5 t FYM ha-1 (115:90:49 N, P2O5 and K2O kg ha-1); and T6 : Targeted Yield 60 q ha-1 with 5 t FYM ha-1 (157:125:70 N, P2O5 and K2O kg ha-1). Partitioning of K into different parts of rice was anlaysed and the result showed that T6 has a significant effect on it. Highest concentration of K in root, leaves, stem, panicle and grain (0.353, 1.730, 2.510, 0.441 and 0.275%, respectively) was found in T6. STCR based fertilizer with 5 tonnes FYM ha-1 application significantly influenced the different fractions of soil K and the maximum available potassium, which is present in the form of water-soluble, exchangeable, and non-exchangeable forms, equilibrium with each other, were also found to be maximum in treatment T6. The study based on STCR demonstrated that STCR based integrated use of fertilizers and manure for targeting yield can produce targeted yield without deteriorating soil fertility.