Age, Dr. A.B.NAVGHARE, NAGESH RAJENDRA.2024-01-072024-01-072023-01-12NAVGHARE, NAGESH RAJENDRA. (2022). Effect of various levels of phosphorus on p dynamics, yield and nutrient uptake by cotton in Vertisol.Department of Soil Science and Agricultural Chemistry, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. M. Sc. 2022. Print. xiv, 103p. (unpublished).https://krishikosh.egranth.ac.in/handle/1/5810205910The present investigation entitled on “Effect of various levels of phosphorus on P dynamics, yield and nutrient uptake by cotton in Vertisol” was carried out at Research Farm, Cotton Research Unit, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during kharif season of 2021-2022. The experiment was laid out in Randomized Block Design with eight treatments replicated in thrice. The recommended dose of fertilizer 120:60;60 NPK kg ha-1 was applied as per treatments. The variety of cotton PDKV JKL116 was used to present investigation. Similarly, Nano DAP was applied at time of seed treatment and foliar application at 30 DAS as per treatments. Initial and after harvest of cotton soil samples and plant samples were collected and analyzed by following standard procedure. The root samples were collected and analyzed at square and boll formation stage of cotton. The result revealed that, the plant height, number of branches, number of bolls per plant, seed cotton and stalk yield of cotton were recorded significantly highest with the application of 100% NPK and found at par with the application of N75 P75 K100+ Nano DAP (ST @ 5 ml / kg seed & FS @ 0.2 % at 30 DAS). Significantly highest content and total uptake of the N, P, K, and S were recorded with application of 100% NPK which found at par with N75 P75 K100+ Nano DAP (ST @ 5 ml / kg seed & FS @ 0.2 % at 30 DAS). However, the inorganic fraction of phosphorus viz Ca-P, Al-P and Fe-P were recorded significantly highest with 100% NPK which found at par with N75 P75 K100+ Nano DAP (ST @ 5 ml / kg seed & FS @ 0.2 %at 30 DAS). The significantly highest value of total organic phosphorous was recorded in 100% NPK and found at par with N75 P75 K100+ Nano DAP (ST @ 5 ml / kg seed & FS @ 0.2 % at 30 DAS). The highest phosphorous use efficiency was recorded with application of N50 P50 K100+ Nano DAP (ST@ 5 ml / kg seed & FS @ 0.2 % at 30 DAS). Whereas, the root CEC, root oxidase activity and root alkaline phosphatase activity were recorded significantly highest with application of 100% NPK and found at par with the application of N75 P75 K100+ Nano DAP (ST @ 5 ml / kg seed & FS @ 0.2 % at 30 DAS). The Significantly highest available nitrogen, phosphorus and potassium were recorded in the 100% NPK and found at par with N75 P75 K100+ Nano DAP (ST @ 5 ml / kg seed & FS @ 0.2 %at 30 DAS). The pH, EC, OC CaCO3, available S, Zn, Cu, Fe and Mn and were slightly improved with the application of 100 % NPK. From the present investigation it can be concluded that, the application of 100 % recommended NPK dose and 75 % N, P,100 % K recommended dose with 0.2 % foliar application of Nano DAP were recorded higher seed and stalk yield of cotton, nutrient uptake by cotton and found equally beneficial to phosphorus dynamics of the soil, root chemical properties, phosphorous use efficiency and slight improvement in residual fertility of soil.EnglishThesis