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.

Isoflavone reductase (IFR) is a key enzyme controlling isoflavone synthesis and widely involved in response to various stresses. In this study, the IFR genes in four Gossypium species and other 7 species were identified and analyzed in the whole genome, and the physicochemical properties, gene structures, cis-acting elements, chromosomal locations, collinearity relationships and expression patterns of IFR genes were systematically analyzed. 28, 28, 14 and 15 IFR genes were identified in Gossypium hirsutum, Gossypium barbadense, Gossypium arboreum and Gossypium raimondii, respectively, which were divided into five clades according to the evolutionary tree and gene structure. Collinear analysis showed that segmental duplication and whole genome duplication were the main driving forces in the process of evolution, and most genes underwent pure selection. Gene structure analysis showed that IFR gene family was relatively conserved. Cis-element analysis of promoter showed that most GhIFR genes contain cis-elements related to abiotic stresses and plant hormones. Analysis of GhIFR gene expression under different stresses showed that GhIFR genes were involved in the response to drought, salt, heat and cold stresses through corresponding network mechanisms, especially GhIFR9A. Phenotypic analysis after silencing GhIFR9A gene by VIGS was shown that GhIFR9A gene was involved in the response to salt stress. This study laid a foundation for the subsequent functional study of cotton IFR genes.

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.

Timely harvesting is an important prerequisite for quality standardization in the traditional Chinese medicine industry. To determine the harvest time of Artemisia argyi and clarify the influence of meteorological factors (MFs) on the harvest time, we selected two excellent germplasm resources, namely, “Nanyang 1” (NY) and Luoyang Artemisia argyi (LY), as examples. We examined the changes in yield, quality, and related traits on 11 sampling dates (SDs) after the six true-leaf stage. Additionally, we analyzed the relationship between eight MFs on different SDs and yield, as well as quality indices. The results show that the SDs and MFs have a significant impact on yield and quality. The dynamic changes in growth traits and dry matter accumulation characteristics of NY and LY were basically consistent. From 75 to 90 d, Artemisia argyi was in the middle and late stages of the transition from vegetative growth to reproductive growth, during which the amount of dry matter accumulation stabilized. The leaves are the most representative medicinal part, with the comprehensive values of the LY leaf yield and main medicinal ingredient contents reaching their maximum at 75 d; the comprehensive values of the NY leaf yield and main volatile ingredient contents reached their maximum at 75 d, while the comprehensive value of the flavonoid and phenolic acid contents reached their maximum at 90 d. Therefore, LY is suitable for harvesting at 75 d, while NY can be harvested at either 75 or 90 d, depending on the harvest goals. In addition, the mean daily minimum temperature (MDMNT), effective accumulated temperature above 10 °C (≥10 °C EAT), and mean temperature daily range (MTDR) were found to be key MFs affecting harvest time. The dry matter accumulation of the roots and stems was significantly positively correlated with the MDMNT (p < 0.01). The dry matter accumulation of the leaves was significantly positively correlated with ≥10 °C EAT (p < 0.05). The total volatile oil content was significantly positively correlated with the MTDR (p < 0.05). These show that meteorological factors affect the harvest time in production practice. This study provides scientific support for determining the harvest time and managing the cultivation of Artemisia argyi.

Water deficiency and low water use efficiency severely constrain wheat yield in dryland regions. This study aimed to identify suitable tillage methods and straw management to improve dry matter production, grain yield, and water use efficiency of wheat in the dryland winter wheat–summer bean (hereafter referred to as wheat-soybean) double-cropping system. A long-term located field experiment (onset in October 2009) with two tillage methods—plowing (PT) and rotary tillage (RT)—and two straw management—no straw mulching (NS) and straw mulching (SM)—was conducted at a typical dryland in China. The wheat yield and yield component, dry matter accumulation and translocation characteristics, and water use efficiency were investigated from 2014 to 2018. Straw management significantly affected wheat yield and yield components, while tillage methods had no significant effect. Furthermore, the interaction of tillage methods and straw management significantly affected yield and yield components except for the spike number. RTSM significantly increased the spike number, grains per spike, 1000-grain weight, harvest index, and grain yield by 12.5%, 8.4%, 6.0%, 3.4%, and 13.4%, respectively, compared to PTNS. Likewise, RTSM significantly increased the aforementioned indicators by 14.8%, 10.1%, 7.5%, 3.6%, and 20.5%, compared to RTNS. Mechanistic analysis revealed that, compared to NS, SM not only significantly enhanced pre-anthesis and post-anthesis dry matter accumulation, and pre-anthesis dry matter tanslocation to grain, but also significantly improved pre-sowing water storage, water consumption during wheat growth, water use efficiency, and water-saving for produced per kg grain yield, with the greatest improvements obtained under RT than PT. Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) analysis confirmed RTSM’s yield superiority was mainly ascribed to straw-induced improvements in dry matter and water productivity. In a word, rotary tillage with straw mulching could be recommended as a suitable practice for high-yield wheat production in a dryland wheat-soybean double-cropping system.

Ridge and furrow planting is a prevalent drought-resistant cultivation technique in dryland regions. Notably, the effects of this technology on crop grain yield and quality in dryland maize–wheat double-cropping systems remain limited. This study utilized a long-term positioning experiment initiated in 2004, which included five treatments: a permanent ridge and furrow with a border ridge of 133 cm row space (PRFBR); a ridge and furrow created each year with a border ridge of 133 cm row space (EYRFBR); a permanent ridge with a normal ridge of 100 cm row space (PRFNR); a ridge and furrow created each year with a normal ridge of 100 cm row space (EYRFNR), and a conventional flat planting pattern according to the local farmer (CF). The crop grain yield in 2015–2021, as well as the protein and phosphorus (P) and potassium (K) content in maize and wheat grains, and the protein components in winter wheat grains in 2020–2021 were investigated. The results showed that, compared to CF, all four ridge and furrow planting patterns significantly enhanced crop yield in dry and normal years, and the effects varied depending on crop species, with increases of 45.3–97.8% for wheat and 11.0–33.8% increases annually in dry years; and 24.5–51.6% increases for maize and 12.2–37.5% increases annually in the normal years. EYRFBR treatment increased wheat grain P and K content by 24.3% and 13.7%, as well as increasing the total protein, albumin, gliadin, soluble protein, and storage protein content by 9.7%, 22.3%, 9.6%, 14.5%, and 5.6%, whereas PRFNR reduced the glutenin content and glutenin/gliadin ratio in winter wheat grains by 5.1% and 10.9%, respectively. The yield achieved with a permanent ridge and furrow (PRF) surpassed that achieved when the ridge and furrow was created anew each year (EYRF), yet the normal ridge width (NR) outperformed the border ridge width (BR). However, the P, K, protein, and protein component content in wheat grains under EYRF was superior to that under PRF. Comprehensive evaluations through principal component analysis (PCA) and TOPSIS analysis consistently demonstrated that the EYRFBR treatment delivered optimal performance in yield and quality for winter and annual, while PRFNR achieved superior yield for summer maize. Consequently, in dryland maize–wheat double-cropping systems, an EYRFBR planting pattern should be recommended for high-yield and high-quality wheat production; however, the PRFNR planting pattern is more suitable for summer maize production.