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Nutrient use efficiency is crucial for increasing crop yield and quality while reducing fertilizer inputs and minimizing environmental damage. The experiments were carried out in silty clay loam soil of Lalitpur, Nepal, to examine how different amounts of nitrogen (N), phosphorus (P), and potassium (K) influenced crop performance and nutrient efficiency indices in wheat during 2019/20 and 2020/21. The field experiment comprised three factorial randomized complete block designs that were replicated three times. N levels (100, 125, 150 N kg ha-1), P levels (25, 50, 75 P2O5 kg ha-1), and K levels (25, 50, 75 K2O kg ha-1) were three factors evaluated, with a total of 27 treatment combinations. Grain yields were significantly increased by N and K levels and were optimum @ 125 kg N ha-1 and @ 50 kg K2O ha-1 with grain yields of 6.33 t ha-1 and 6.30 t ha-1, respectively. Nutrient levels influenced statistically partial factor productivity, internal efficiency, partial nutrient budget, recovery efficiency, agronomic efficiency, and physiological efficiency of NPK for wheat. Nutrient efficiency was found to be higher at lower doses of their respective nutrients. Higher P and K fertilizer rates enhanced wheat N efficiencies, and the case was relevant for P and K efficiencies as well. Wheat was more responsive to N and K fertilizer, and a lower rate of P application reduced N and K fertilizer efficiency. This study recommends to use N @ 125 kg ha-1, P2O5 @ 25 kg ha-1 and K2O @ 50 kg ha-1 as an optimum rate for efficient nutrient management in wheat in mid-hills of Nepal.

The optimum dose of fertilizers for crops varies with soil, agro-ecology, and crop management practices. Optimizing application dose is critical to reduce nutrient loss to the environment and increase nitrogen use efficiency (NUE), crop yields, and economic return to farmers. An experiment was conducted to determine the optimum N dose for increasing maize (Zea mays L. cv, Manakamana-3) yield, NUE, and farm profits under rainfed conditions. Five levels of N (0, 60, 120, 180, and 240 kg ha−1), and a non-fertilized treatment were tested in a randomized complete block design with three replications. Effects of each treatment on yield and yield attributing traits, plant lodging and Sterility (plants with no cob or grain formation), NUE, and stay green trait of maize were recorded. Application of N above 120 kg ha−1 (N120) did not have any significant effects on yield and yield components. Nitrogen, at N120 and above, produced highly fertile plants (though sterility slightly increased at N180 and N240), higher N uptake, and lower dead leaf area (18–27%). N120 produced the highest agronomic; yield increase per unit of N application (AEN—26.89 kg grain kg−1 N) and physiological efficiency of N (PEN—42.67 kg grain kg−1 N uptake), and net benefit (USD 500.43). Considering agronomic, economic, and NUE factors, an N dose of 120 kg ha−1 was found optimum for the cultivation of rainfed maize (Manakamana-3) under sandy loam soil.

Knowledge about the soil fertility status and mapping their spatial distribution play a crucial role for sustainable planning of particular area. Thus, a study was conducted to assess the soil fertility status of the Agricultural Research Station, Bijayanagar, Jumla, Nepal. The farm is situated at the latitude 29.273656°N and longitude 82.180967°E as well altitude 2370masl. The total 18 samples were collected randomly at a depth of 0-20 cm by using soil sampling auger. A GPS device was used for determination of geographical position of soil sampling points. The collected samples were analyzed following standard analytical methods in the laboratory of Soil Science Division, Khumaltar. The Arc-GIS 10.1 software was used for the soil fertility distribution mapping. The observed data revealed the structure was sub-angular blocky, whereas colour were dark grayish brown and very dark brown. The sand, silt and clay content were ranged 27-47%, 33.10-61.10% and 11.90-23.90%, respectively and categorized loam and silt loam in texture. The soil pH was moderately acidic to moderately alkaline (5.45-7.66) and very low in available boron (0.01-0.28 mg/kg) and sulphur (0.59-6.23 mg/kg). Moreover, very low to very high available iron (15.90-300.50 mg/kg), very low to high available manganese (1.46-12.88) and low to high organic matter (2.07-6.53%). Similarly, medium to high total nitrogen (0.14-0.23%), available potassium (40-255 mg/kg) and zinc (1.12-8.26 mg/kg). Correspondingly, high available calcium (1632-2880 mg/kg) and magnesium (98-456 mg/kg), and very high available phosphorus (64.2-257.2 mg/kg) and copper (2.58-12.16 mg/kg). The determined soil test data can be used for sustainable soil management as well as developing future research strategy in the farm.

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