Optimized nitrogen fertilizer application strategies under supplementary irrigation improved winter wheat (Triticum aestivum L.) yield and grain protein yield

Effect of Nitrogen in Combination with Different Levels of Sulfur on Wheat Growth and Yield

As macronutrients, management of nitrogen (N) and sulfur (S) is prime in importance when wheat is cultivated. Both have a significant impact on the improvement of growth and yield attributes. In addition, S and N also play an imperative role in the enhancement of seed protein contents. However, the need of the time is the selection of their optimum application rate for the achievement of maximum wheat productivity. That is why the current study was planned to examine the impact of variable application rates of S and N on wheat. There are 12 treatments, i.e., control (no nitrogen (0N) + no sulfur (0S)), 40 kg/ha N (40N + 0S), 80 kg/ha N (80N + 0S), 120 kg/ha N (120N + 0S), 30 kg/ha sulfur (30S), 40N + 30S, 80N + 30S, 120N + 30S, 60 kg/ha sulfur (60S), 40N + 60S, 80N + 60S, and 120N + 60S, applied in three replications. The results showed that plant height, grains/spike, spike/m², and 1000 grain weight were significantly improved by the addition of 120N + 60S. A significant enhancement of grain N contents, N uptake, and protein contents of wheat validated the efficient role of 120N + 60S over 0N and 0S. In conclusion, 120N + 60S is a better treatment for the achievement of maximum wheat yield. More investigations under variable soil textures and climatic conditions are suggested under different climates to declare 120N + 60S as the best amendment for wheat growth and yield improvement.

Nitrogen and Chemical Control Management Improve Yield and Quality in High-Density Planting of Maize by Promoting Root-Bleeding Sap and Nutrient Absorption

High-density planting aggravates competition among plants and has a negative impact on plant growth and productivity. Nitrogen application and chemical control can improve plant growth and increase grain yield in high-density planting. Our experiment explored the effects of nitrogen fertilizer and plant growth regulators on maize root-bleeding sap, phosphorus (P) and potassium (K) accumulation and translocation, and grain yield and quality in high-density planting. We established a field study during the 2017 and 2018 growing seasons, with three nitrogen levels of N100 (100 kg ha-1), N200 (200 kg ha-1), and N300 (300 kg ha-1) at high-density planting (90,000 plants ha-1), and applied Yuhuangjin (a plant growth regulator mixture of 3% DTA-6 and 27% ethephon) at the 7th leaf. Our results showed that N200 application combined with chemical control could regulate amino acid and mineral nutrient concentration delivery rates in root-bleeding sap and improve its sap rate. Also, the treated plant exhibited higher P and K uptake and translocation ability. Furthermore, chemical control and N200 treatment maintained a high level of ribulose-1,5-bisphosphate carboxylase (RuBPCase), phosphoenolpyruvate carboxylase (PEPCase), nitrate reductase (NR), and glutamine synthetase (GS) enzymatic activities in leaves. In addition, plant growth regulator and nitrogen application improved the enzymatic activities of GS, glutamate dehydrogenase (GDH), and glutamic pyruvic transaminase (GPT) and the contents of crude protein, lysine, sucrose, and soluble sugar in grain and ultimately increased maize yield. This study suggests that N200 application in combination with chemical control promotes root vitality and nutrient accumulation and could improve grain yield and quality in high-density planting.

Nutrient use efficiency (NUE) of wheat (Triticum aestivum L.) as affected by NPK fertilization

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.