Organic fertilizer substitution is an effective measure for increasing both the quantity and quality of wheat grain while reducing chemical fertilizer input. However, the effects of reducing nitrogen (N) fertilizer combined with organic fertilizer substitution on grain yield, grain protein content and protein yield, plant N accumulation and translocation, N use efficiency, soil fertility, N apparent surplus and nitrate-N residue in rain-fed drought-prone areas remains limited. In this study, field experiments were conducted over four consecutive seasons (2019-2023) at two sites with four treatments: zero N application (ZN), farmer N application (FN), reduced 20% N of FN (RN), and organic fertilizer substituting 20% N of RN (OSN). The results showed that compared with the ZN treatment, the FN, RN and OSN treatments increased grain yield and its components, grain protein content and protein yield, aboveground N accumulation at the anthesis and maturity stages, pre-anthesis N translocation, post-anthesis N accumulation, N use efficiency, soil fertility. Compared with RN and FN, OSN increased grain yield by 17.12% and 15.03%, grain protein yield by 3.31% and 17.15%, grain N accumulation by 17.78% and 15.58%, and N harvest index by 2.63% and 4.45% averaged across years and sites, respectively. Moreover, OSN increased the contents of organic matter, total N, available P and available K in both 0-20 and 20-40 cm soil layers, decreased N apparent surplus and nitrate-N residue in 0-100 cm, and pH in both 0-20 and 20-40 cm soil layer. Fundamentally, this study suggests that integrating a 20% reduction N from conventional farmer practices with the utilization of organic fertilizer to replace 20% of the chemical N fertilizer (OSN) represents an effective strategy. This approach shows promise in enhancing wheat grain yield, grain protein yield, and N use efficiency. Additionally, it supports the improvement of soil fertility while simultaneously reducing soil nitrate-N residues and the apparent surplus of N in rain-fed drought-prone regions.

Finding field management techniques that increase crop output while protecting soil sustainability is essential for maintaining a long-term food supply in a changing environment. However, comprehensive evaluation of the effects of nitrogen (N) reduction combined with organic fertilizer on grain yield, N use efficiency (NUE), water use efficiency (WUE), and soil organic carbon (SOC) and total N (TN) contents of winter wheat–summer maize double cropping systems in drought-prone areas remains limited. Therefore, a 3-year field experiment (2018–2021) was conducted in a winter wheat–summer maize double cropping system with five treatments: no N fertilizer (CK), conventional farmer fertilization (CF), recommended fertilization (R), organic N substitution of 20% of the recommended synthetic N (R₂₀), and organic N substitution of 40% of the recommended synthetic N (R₄₀). When results were averaged from 2018 to 2021, R₂₀ had the highest annual grain yield, which increased by 42.15%, 7.69%, 7.58%, and 12.50% compared with CK, CF, R, and R₄₀, respectively. Compared with CF, R₂₀ increased winter wheat and summer maize NAE, NPFP, NUE, and WUE. In addition, the soil organic carbon content of R₂₀ and R₄₀ treatment increased with the increase in years. In conclusion, R₂₀ was considered ideal for improving crop yield, promoting soil fertility, and increasing the fertilizer utilization rate in a semiarid winter wheat–summer maize rotation.

Leaf nitrogen (N), phosphorus (P), and potassium (K) stoichiometry can reflect plant strategies of nutrient allocation, which play key roles in ensuring food security and maintaining nutrient balance in the agroecosystem. Arbuscular mycorrhizal fungi (AMF) inoculation is an effective and green management measure affecting nutrient uptake and utilization strategies, especially in the agroecosystem. However, the interplay between AMF and leaf nutrient stoichiometry that is important for sustainable agriculture remain underexplored. Therefore, the efficacy of AMF in improving leaf nutrients of host plants in agricultural ecosystems were tested with meta-analysis by 1932 pairs of observations in research publications from 1995 to 2022. Overall analysis showed that AMF inoculation increases leaf N, P, and K by 8.75%, 24.61%, and 13.54%, respectively. Moreover, leaf P: K increased by 11.74% by AMF inocula, but leaf N: P and N: K of host plants decreased by 15.38% and 5.52%, respectively. Furthermore, the AMF effect on leaf nutrient stoichiometry was significantly regulated by species, life cycle, and growth habits of host plants. The prominent efficacy of AMF was higher for leaf P in fruit (30.06%), perennial (30.19%), and woody plants (31.6%) than other groups. Moreover, AMF effects on leaf N: P: K stoichiometry of inoculated crops varied depending on the identity of AMF. The Glomeraceae (especially Rhizophagus genera) increased more leaf P content than other AMF families. Thus, the leaf nutrient of host plants significantly increased by AMF inocula, especially leaf P content in the agroecosystem. The effect of AMF on leaf N: P: K stoichiometry was related to plant species, plant life cycle, plant growth habits, and the identity of AMF. These findings highlight the response of AMF to the strategies of nutrient in host plants and provide a theoretical and applicable way for better crop yield and sustainable agriculture.

Benefiting from the high–farmland construction program in China, one–off irrigation can be guaranteed in most fields in semi–humid drought–prone areas in China. However, little information is available on water and nitrogen (N) management in wheat production under this condition. This study aimed to explore the effects of alternative furrow irrigation (AFI) and topdressing N fertilizer (TN) on wheat productivity under a no–till ridge–furrow planting system in semi–humid drought–prone areas. The experimental design was as follows: two furrow irrigation (FI) methods, namely, EFI (every furrow irrigation) and AFI (alternative furrow irrigation) with 75 mm at the jointing stage were set as the main treatments. Two topdressing N (TN) patterns, namely, NTN (0 kg ha⁻¹ of N) and TN (60 kg ha⁻¹ of N) along with irrigation were set as the secondary treatments. Moreover, a traditional planting practice with no irrigation and no topdressing N (NINTN) was set as control. In 2018–2020, a field experiment was carried out to investigate the effects on soil water, leaf chlorophyll relative content (SPAD) and net photosynthetic rate (Pn), aboveground dry matter assimilates, grain yield, water use efficiency (WUE) and economic benefit. We found that both FI methods and TN patterns significantly influenced soil water content. Compared with NINTN, the soil water content in each combination of the FI method and TN pattern was effectively improved at the booting and anthesis stages, leading to the significant increase in SPAD and Pn in leaves, post–anthesis dry matter accumulation (POA), grain yield, WUE and economic benefit of winter wheat. Compared with the EFI, averaged across years and TN patterns, the AFI technique increased the soil water storage at booting and anthesis stages and significantly improved the Pn at early milk (4.9%) and early dough (7.5%) stages, POA (40.6%) and its contribution to grain (CRPOA, 27.6%), the grain yield (10.2%), WUE (9.1%) and economic benefit (9.1%). In addition, compared with the NTN, the TN pattern significantly increased the water computation by wheat from booting to maturity, enhanced leaf Pn after anthesis and POA, and finally resulted in the increase in grain yield (14.7–21.9%) and WUE (9.6–21.1%). Thus, the greatest improvement in the leaf photosynthetic characteristics, aboveground dry matter assimilates, grain yield, WUE and economic benefit was achieved under AFITN treatment. Above all, it can be concluded that the AFITN with AFI of 75 mm and TN of 60 kg ha⁻¹ at jointing was an alternative management strategy for optimizing yield formation and water use of winter wheat. This study provided new insights into improving wheat productivity in drought–prone areas where one–off irrigation can be guaranteed.

The tillage method and straw returning are the two most important agronomic measures for crop production, but their combined effects on nutrient accumulation and utilization and grain yield in dryland winter wheat (Triticum aestivum L., namely wheat)–summer maize (Zea mays L., namely maize) double-cropping system are still poorly understood. The present study delves into the impact of the tillage method and straw returning on yield and nutrient accumulation and utilization in wheat–maize double-cropping system based on a field split-plot positioning experiment (started in October 2009). Three tillage methods—plowing (PT, 30–35 cm in depth), rotary tillage (RT, 12–15 cm in depth), no-tillage (NT)—and two straw management—zero straw returning (S0) and straw returning (SR)—were assigned to the main plots and subplots, respectively, thus encompassing six distinct treatments of PTS0, PTSR, RTS0, RTSR, NTS0, and NTSR. The grain yield and its components; the nitrogen (N), phosphorus (P), and potassium (K) accumulation at maturity; and the internal efficiency of N, P, and K in wheat and maize from 2018 to 2022 were investigated. The results indicated that in the experimental years, tillage methods and straw management significantly affected wheat, maize, and annual yield. Compared with NT, RT significantly increased wheat yield by 9.5% and maize K accumulation by 5.8%, and PT significantly increased wheat K accumulation by 11.1% and the yield and N, P, and K accumulation of maize by 6.3%, 7.8%, 8.9%, and 5.3%. Compared with RT, PT significantly increased yield and K accumulation in wheat and yield and N and P accumulation in maize. Compared with NTSR, PTSR significantly increased the yield and N, P, and K accumulation in wheat, but it did not affect yield and nutrient accumulation in maize; RTSR significantly increased wheat yield while it significantly decreased yield and N, P, and K accumulation in maize. Compared with RTSR, PTSR significantly increased the yield and N, P, and K accumulation by 4.0%, 19.5%, 19.6%, and 7.0% in wheat, respectively, and 7.5%, 6.1%, 13.3% and 13.6% in maize. Under the same tillage method, compared with S0, SR significantly increased crop yield and N, P, and K accumulation by 2.4–25.4%, 8.5–43.3%, 12.9–37.8%, and 11.0–51.0%, but it significantly reduced wheat K internal efficiency and maize N, P, K internal efficiency. The effectiveness of straw management on crop yield and N, P, and K accumulation was greater than that of tillage methods. Therefore, the combination of plowing tillage with straw returning (PTSR) is an effective tactic to promote crop yield in dryland wheat–maize double-cropping system. This study offered insights for achieving high yield by regulating the accumulation and internal efficiency of plant N, P, and K nutrients in wheat–maize double-cropping system in drought-prone areas and environments similar to the study areas.