The long-term sustainability of rice-wheat system (RWS) requires robust interventions such as recycling of rice straw (RS) to improve soil health and minimal impact on environment. Therefore, the dynamic adjustments in fertilizer-N application with RS incorporation that impacts crop productivity, N availability, N use efficiency (NUE) and soil enzymatic activity are required. We investigated the long-term impacts of four rates of RS incorporation (0, 5.0, 7.5 and 10.0 Mg ha⁻¹ year^-1; RS₀, RS_5.0, RS_7.5 and RS_10.0) and four rates of fertilizer-N (0, 90, 120 and 150 kg N ha^-1; N₀, N₉₀, N₁₂₀ and N₁₅₀) application in different combinations on N dynamics in soils, enzyme activity, crop yields and NUE. Results revealed that fertilizer-N application significantly (p<0.05) increased the grain yield, NUE and soil N pools in response to increasing RS incorporation rates. Fertilizer-N application combined with RS rates (RS_5.0-RS_7.5) resulted in a significantly higher mineral-N (NH₄⁺-N + NO₃⁻–N) concentration compared with no-straw and no-N application (N₀ RS₀), which decreased with increased soil depth. The combined application of fertilizer-N and RS incorporation significantly increased soils’ enzymatic activity (urease and L-asparaginase) and glomalin related soil protein (TG). The crop (rice and wheat) yields (grain and straw) were significantly higher with fertilizer-N application of 120 kg N ha^-1 along with RS incorporation of 7.5 Mg ha^-1 yr^-1 (N₁₂₀ RS_7.5). The physiological efficiency of N (PE_N) was significantly improved with fertilizer-N application and RS incorporation from 35.6 to 73.2 kg N kg⁻¹ in rice and 35.7–64.9 kg N kg⁻¹ in wheat. The reciprocal internal use efficiency of N (RIUE_N) ranged from 14.8 to 19.5 kg Mg^-1in rice and from 17.5 to 21.5 kg Mg^-1 in wheat. Average net returns and the benefit-cost ratio for rice and wheat were significantly increased with N₁₂₀ RS_7.5, compared with N₉₀ RS_7.5 treatment. The higher rate of fertilizer-N application at similar RS incorporation rate (N₁₅₀ RS_7.5) did not result in significant change in crop yields and economic indices, compared with N₁₂₀ RS_7.5. Therefore, application of 120 kg N ha^-1 is the optimum rate with RS incorporation at 7.5 Mg ha^-1 yr^-1 for increased productivity, NUE and economic returns, while avoiding environmental implications associated to open field straw burning in north-western India.

稻麦系统的长期可持续性要求采取强有力的干预措施，例如回收稻草（RS），以改善土壤健康并最小化对环境的影响。因此，需要动态调整氮磷钾肥的施用量，影响作物的生产力，氮素的利用率，氮素的利用效率（NUE）和土壤酶活性。我们调查了4种RS掺入率（0、5.0、7.5和10.0 Mg ha - ¹年^-1 ; RS ₀，RS _5.0，RS _7.5和RS _10.0）和4种施氮量（0的长期影响，90、120和150 kg N ha ^-1； N ₀，N ₉₀，N ₁₂₀和N ₁₅₀）以不同的组合方式应用到土壤中的氮动力学，酶活性，农作物产量和NUE。结果表明，随着RS掺入率的增加，施氮肥显着（p < 0.05）增加了谷物产量，NUE和土壤氮库。与不施用秸秆和不施用氮肥（N ₀）相比，施用氮肥和氮肥施用率（RS _5.0 -RS _7.5）显着提高了矿质氮（NH ₄ ⁺ -N + NO ₃ ^-- N）的浓度。RS ₀），但随着土壤深度的增加而降低。氮肥和氮肥的组合施用显着提高了土壤的酶活性（脲酶和L-天冬酰胺酶）和胶质瘤相关土壤蛋白（TG）。施用120 kg N ha ^-1的氮肥，以及掺入7.5 Mg ha ^-1 yr ^-1（N ₁₂₀ RS _7.5）的RS ，可显着提高作物（稻米和小麦）的产量（谷物和稻草）。N的生理效率（PE _Ñ）与氮肥申请显著改善和RS掺入从35.6 73.2千克氮千克^-1在水稻和35.7-64.9公斤氮千克^-1在小麦中。氮在水稻中的互惠使用效率（RIUE _N）为14.8至19.5 kg Mg ^-1，而小麦则为17.5至21.5 kg Mg ^-1。平均净回报和效费比对于水稻和小麦用N分别显著增加₁₂₀ RS _7.5，与N进行比较_90个RS _7.5治疗。与N ₁₂₀ RS _7.5相比，在相似的RS掺入率下（N ₁₅₀ RS _7.5）较高的肥料氮肥施用率并未导致作物产量和经济指标发生显着变化_。因此，应用120 kg N ha ^-1是在7.5 Mg ha ^-1 yr ^-1时掺入RS的最佳速率，以提高生产率，NUE和经济回报，同时避免了印度西北部露天秸秆焚烧对环境的影响。