Impact of Long-term Manuring and Fertilization on Micronutrient Status under Sorghum-wheat Cropping Sequence in Vertisols

A long-term fertilizer experiment has been under progress since 1988-89 at LTFE field department of soil science PGI, Dr. PDKV, Akola with sorghum wheat cropping sequence consisting of twelve treatments and replicated four times in a randomized block design. The present study was conducted to assess the influence of continuous fertilizer and manure application on micronutrient availability in long term fertilizer experiment during 2023-24. Long term application of organic and inorganic fertilizers in combination (100 % NPK+ FYM @ 5 t ha -1, FYM @ 10 t ha -1 and 75% NPK + 25 % N through FYM) or balanced fertilization (100% NPK, 150% NPK and 100 % NPK + Zn@ 2.5 kg ha -1) for about 36th cropping cycles lead to marked increase in soil micronutrient availability. All four micronutrient cations were significantly higher under INM treatments. On an average, the INM treatments (T8) had 53.29, 22.86, 69.56 and 34.44 % higher content of available Fe, Mn, Zn and Cu respectively, over the balance fertilizer (T2). However, continuous cultivation of crops without or imbalanced nutrient supply (50% NPK, 100 %NPK (-S), 100 % NP, 100 % N and Control) lead to decline in soil micronutrient status. Balanced fertilization and organic matter addition has played an important role in improving micronutrient status in soil after 36 years of cropping cycles.