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Low and unstable fruit yield, poor quality of fruits, and excessive fruit dropping are major problems in a lime crop and are due to either micronutrient deficiencies or nutrient imbalance. A study was conducted to assess the micronutrient status in a lime orchard at the Central Soil and Water Conservation Research and Training Institute (CSWCRTI)'s research farm in Kota, Rajasthan, India. Plant and soil samples were collected during September and October in 2006-2007. The micronutrients extracted with diethylenetriaminepentaacetic acid (DTPA) in soils were in the order of manganese (Mn) > iron (Fe) > zinc (Zn) > copper (Cu). The mean values of DTPA Mn, Fe, Zn, and Cu in surface soils varied from 13.98 to 22.70, 2.48 to 8.66, 0.79 to 1.19, and 0.14 to 0.46 mg kg-1, respectively, whereas in subsurface soils they varied from 12.94 to 23.06, 4.84 to 6.52, 0.51 to 0.83, and 0.07 to 0.20 mg kg-1, respectively. Results reveal that except for Fe, the other DTPA-extractable micronutrients decreased with depth. Total Mn, Fe, Zn, and Cu in plant leaves varied from 22 to 83, 70 to 630, 40 to 932, and 37 to 3057 mg kg-1, respectively, indicating greater or toxic concentrations of total micronutrient in leaf samples. Total Mn, Fe, Zn, and Cu in petiole samples varied from 7 to 60, 235 to 574, 70 to 827, and 101 to 2623 mg kg-1, respectively. High concentration of Cu and Zn in leaves resulted in Fe and Mn deficiencies (exhibited as leaf chlorosis) in lime plants. Results of the study indicated that Fe and Mn deficiencies are major disorders in lime plantation. Similarly, the measure of DTPA-extractable micronutrients showed the low statuses of Fe and Cu and marginal status of Zn in soils along the Chambal region. [ABSTRACT FROM AUTHOR]

We studied the effect of integrated nutrient management (INM) combinations on supplement of plant nutrient for quantitative and qualitative fruit production in sapota. Thus, 17 combinations of INM practices were evaluated on fruit yield of sapota and nutrient availability in a Vertisol of Chambal region, India. The results demonstrated that almost all treatment combinations comprised of recommended dose of fertilizer (RDF), i.e. 1,000:500:500 g NPK plant−1 with application of organic and inorganic sources of nutrients had a significant effect on the fruit yield of sapota, soil microbial biomass, NPK content of leaf, fruit and soil over control (T1). Among different treatments, application of 2/3rd part of RDF + 50 kg FYM + 250 g Azospirillum + 250 g Azotobacter plant−1 (T11) significantly enhanced the number of fruits plant−1 (327.88), yield plant−1 (29.03 kg) and yield ha−1 (4.52 t). However, the soil microbial count of fungi (8.89 cfu g−1 soil), bacteria (11.19 cfu g−1 soil) and actinomycetes (5.60 cfu g−1 soil) at fruit harvest was higher under the 2/3 of RDF +10 kg vermicompost + 250 g Azospirillum + 250 g Azotobacter plant−1 (T15). The leaf nitrogen content (N, 2.03%) was higher in T15, while phosphorus (P, 0.28%) and potassium (K, 1.80%) content were higher in T11. It is evident that treatment T11 increased fruit yield by 32% in Sapota cv. Kalipatti compared to control. Therefore, combined application of nutrient sources proved not only beneficial for enhancing fruit yield of sapota but also sustaining soil health in Chambal region of south-eastern Rajasthan. [ABSTRACT FROM AUTHOR]