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Grain‐filling rate and duration largely affect the grain‐filling capacity, which determines the grain yield of maize (Zea mays L.). Nevertheless, there is little about the mechanism of how various soil mulching practices affect the leaf photosynthetic potential and subsequent grain‐filling capacity of maize. Field experiments were undertaken on rainfed summer maize in northwest China under flat cultivation without mulch (FNM), flat cultivation with straw mulch (FSM), flat cultivation with transparent film mulch (FTF), flat cultivation with black film mulch (FBF), ridge‐furrow cultivation with transparent film mulch (RTF) and ridge‐furrow cultivation with black film mulch (RBF) in 2021 and 2022. This study explored the impact of various soil mulching patterns on soil hydrothermal condition, leaf growth, photosynthetic potential, aboveground dry matter growth and grain‐filling process of rainfed maize. The dynamics of leaf area index (LAI) and grain‐filling were fitted with growth equations, and the relationships of grain‐filling rate, leaf area duration and LAI withering rate were quantified. The results showed that, compared with FNM, other five soil mulching practices improved soil hydrothermal condition, the maximum LAI and leaf expansion rate but reduced leaf withering rate, thereby increasing radiation interception rate (RI) at the grain‐filling stage. The soil mulching practices also increased leaf SPAD value, net photosynthetic rate, photosynthetic nitrogen use efficiency and the aboveground dry matter. Compared with FNM, other five practices extended the effective grain‐filling period and the active period of grain‐filling, increased the maximum and mean grain‐filling rates, improved the 100‐kernel weight and the average kernel per ear (KPE), thereby increasing grain yields by 9.2%, 33.7%, 38.0%, 46.3% and 58.6%, respectively. The functional relationships of grain‐filling rate and accumulated leaf area duration (y = a/(1 + b*exp(−kx))), and the functional relationships of grain‐filling rate and LAI withering rate (y = (a + cx + ex2)/(1 + bx + dx2)) were first proposed. In conclusion, various soil mulching practices improved the soil hydrothermal condition, green leaves growth process and RI, which improved the leaf photosynthetic potential and the grain‐filling capacity, thereby increasing the 100‐kernel weight, KPE and grain yield. This study can help us quantitatively describe and better understand the maize grain‐filling process under various mulching practices. [ABSTRACT FROM AUTHOR]

Ridge–furrow cropping patterns, nitrogen fertilisation and seed rate regulation are popular management strategies for improving crop yields in the semi‐arid areas of Northwest China, but their interactive effects on grain yield and water use efficiency remain poorly understood. In 2020–2021 and 2021–2022, a two‐season field experiment was conducted on winter wheat. There were two cropping patterns (C), ridge–furrow cropping with film mulch (RC) and traditional cropping without mulch (TC), two nitrogen fertilisation rates (N), 0 and 200 kg N ha−1 (N0 and N1) and three seed rates (S), 240, 360 and 480 plants m−2 (S1, S2 and S3). The study was conducted in a split–split design with three replications (randomised blocks) and a total of 24 experimental plots. It was found that the interactive effects of C × N, C × S and N × S were significant on soil temperature (ST), leaf area index (LAI), relative chlorophyll content (SPAD), photosynthetic parameters, grain yield (GY) and water use efficiency (WUE) (p < 0.05), while C × N × S was significant only for LAI, aboveground biomass (AGB), GY and WUE (p < 0.05). Compared with TC and N0, RC and N1 significantly increased SPAD value (2.4% and 15.8%), net photosynthetic rate (Pn) (19.8% and 32.8%), net photosynthetic rate (Pn), transpiration rate (Tr) (7.0% and 15.7%) and the effective PSII quantum production (ΦPSII) (10.7% and 5.0%). The highest GY (6773 kg ha−1 over 2020–2021 and 8036 kg ha−1 over 2021–2022) and WUE (20.03 kg ha−1 mm−1 over 2020–2021, and 21.77 kg ha−1 mm−1 over 2021–2022) of winter wheat were observed under RC + N1 + S2. The findings showed that the RC cropping pattern with fertilisation and seed rate regulation (360 plants m−2) of winter wheat, which is appropriate for ensuring the long‐term sustainability of agricultural production in the semi‐arid regions of Northwest China, enhanced plant growth, photosynthetic traits, yield and water use efficiency. The study might give useful information for enhancing the productivity and water use efficiency of winter wheat in this and other similar climate locations. [ABSTRACT FROM AUTHOR]

The functional structure of territorial space is an important factor for analyzing the interaction between humans and nature. However, the classification of remote sensing images struggles to distinguish between multiple functions provided by the same land use type. Therefore, we propose a framework to combine multi-source data for the recognition of dominant functions at the block level. Taking the Guangdong–Hong Kong–Macau Greater Bay Area (GBA) as a case study, its block-level 'production–living–ecology' functions were interpreted. The whole GBA was first divided into different blocks and its total, average, and proportional functional intensities were then calculated. Each block was labeled as a functional type considering the attributes of human activity and social information. The results show that the combination of land use/cover data, point of interest identification, and open street maps can efficiently separate the multiple and mixed functions of the same land use types. There is a great difference in the dominant functions of the cities in the GBA, and the spatial heterogeneity of their mixed functions is closely related to the development of their land resources and socio-economy. This provides a new perspective for recognizing the spatial structure of territorial space and can give important data for regulating and optimizing landscape patterns during sustainable development. [ABSTRACT FROM AUTHOR]

Water stress can trigger acclimation responses and damage plants. The aim of this study was to evaluate the integrative responses of cotton hydraulic conductance, leaf photosynthesis, and carbon metabolism to short-term drought and subsequent rewatering. A water-controlled pot experiment was conducted in 2020, with soil water drying continuing for one day (D1), two days (D2), and three days (D3) after it reached 40% ± 5% of the soil water holding capacity at the blooming stage of cotton, and the soil was then rewatered to the soil water holding capacity. We investigated how the stem hydraulic conductance, gas exchange, and biochemical traits of cotton were affected by imposed drought stress and subsequent rewatering. The hydraulic characteristics of cotton in the D2 and D3 treatments evolved with damage, complete closure of stomatal conductance, and complete deterioration of photosynthesis, in addition to severe floating changes in the carbon metabolism affected by drought. The leaves' functional characteristics after rewatering cannot be completely recovered to full-irrigation levels, and the recovery extent was strongly linked to the duration. Consequently, it is considered desirable to maintain normal physiological activity during the cotton reproductive period, and the drought episode can be sustained for 1 day in a long-term perspective when the soil water content is depleted to 40% ± 5% of the soil water holding capacity. These results can provide in-depth ideas for better understanding the hydraulic and physiological responses of cotton to drought episodes and rewatering, and they can help drought-affected cotton to cope with future climate change. [ABSTRACT FROM AUTHOR]

Economic benefits and risk premiums significantly affect the production system decision making of farmers and government departments. This study evaluated the economic feasibility and estimated the risk premium of 12 rainfed soybean production systems with various planting densities, fertilization rates and planting patterns by considering the impact of soybean price fluctuation. There were two planting densities (D1: 160,000 plants ha−1 and D2: 320,000 plants ha−1), two fertilization rates (F1: 20 kg ha−1 N, 30 kg ha−1 P, 30 kg ha−1 K; F2: 40 kg ha−1 N, 60 kg ha−1 P, 60 kg ha−1 K) and three planting patterns (F+W0: flat cultivation with no irrigation; R+W0: plastic-mulched ridge-furrow cultivation (PMRF) with no irrigation; R+W1: PMRF with supplemental irrigation of 30 mm at the pod-filling stage). Based on the two-year (2019–2020) field data in a semi-humid drought-prone region of northwest China and soybean price fluctuation from January 2014 to June 2021, the net income (NI) was calculated by considering the impact of soybean price fluctuation and assuming constant soybean production costs. The net present value (NPV) method and the stochastic efficiency with respect to a function (SERF) method were used to evaluate the profitability of protective alternatives and the risk of these alternatives. The results showed that the 12 proposed soybean production systems were economically feasible. Reducing the fertilization rate reduced the input costs, but it did not necessarily result in a decrease in soybean yield and NI. The payback period of all production systems was within two years for farmers investing through loans. High-fertilizer and high-density production systems made personal investment obtain the highest economic benefit in this study, which was not the best investment strategy from the perspective of production-to-investment ratio and environmental protection departments. The preferences of farmers with various risk aversion and environmental protection departments in terms of risk premium were also proposed. The economic and risk assessment framework of this study can enhance the understanding of the adjustment of production systems from different perspectives, and provide strategies for promoting the protection of economic, environmental and socially sustainable agricultural systems. [ABSTRACT FROM AUTHOR]

The characteristics of photosynthesis and grain filling play a significant role in determining maize (Zea mays L.) yield. Planting density and nitrogen (N) rate are two factors affecting the growth, physiology, and grain yield of maize. The coupling effects of planting density and N rate on individual and population photosynthetic rates, grain-filling characteristics, grain yield, water use efficiency (WUE), and N partial factor productivity (NPFP) of two maize cultivars (QS51 and ZD958) under mulched drip fertigation in northwest China were investigated. Three planting densities (D1: 80,000 plants ha−1, D2: 100,000 plants ha−1, and D3: 120,000 plants ha−1) and three N rates (N0: 0 kg ha−1, N180: 180 kg ha−1, and N240: 240 kg ha−1) were designed. The results showed that the population photosynthetic rate, grain yield, WUE, and NPFP were significantly affected by planting density and N rate for both QS51 and ZD958, and their interaction had a significant effect on grain yield, WUE, and NPFP. Nitrogen application significantly improved grain-filling rates compared with N0, but there was no significant difference between N240 and N180. The D2N180 treatment obtained the maximum grain yield (15,693 kg ha−1 for QS51 and 17,644 kg ha−1 for ZD958), WUE (3.42 kg kg−1 for QS51 and 3.05 kg kg−1 for ZD958), and NPFP (98.37 kg kg−1 for QS51 and 83.93 kg kg−1 for ZD958). It was concluded that the optimized planting density and N rate improved grain yield and water-nitrogen use efficiency of QS51 and ZD958 by increasing population photosynthetic rate, grain-filling rate, and grain weight. This study enhanced our understanding of how optimized planting density and N rate maintained the sustainable maize production under mulched drip fertigation in northwest China. [ABSTRACT FROM AUTHOR]

Ridge-furrow planting, supplementary irrigation and density regulation are effective measures to improve crop yields in (semi-)arid and drought-prone regions around the world, but their interactive effects on crop evapotranspiration, plant nitrogen uptake, grain yield and its components, water productivity, nitrogen use efficiency and economic benefit of winter wheat are not fully understood. Field experiments were carried out on winter wheat in a semi-humid but drought-prone region of northwest China during 2020 − 2021 and 2021 − 2022. There were two planting patterns (P): ridge-furrow planting with plastic film mulching on ridges (RF) and conventional flat planting (F), two supplementary irrigation amounts (I): 30 mm supplementary irrigation at both overwintering and returning-green stages (I 60) and no supplementary irrigation (I 0), and three planting densities (D): 240 × 104 plants ha−1 (LD), 360 × 104 plants ha−1 (MD) and 480 × 104 plants ha−1 (HD). The results showed that significant interactive effects of P × I, P × D, I × D and P × I × D on grain yield and water productivity of grain yield (WP g) were obtained, and the interactive effects of P × I, I × D and P × I × D on partial factor productivity of nitrogen (NPFP) and net income (NI) were significant. Compared with F, RF increased grain yield by 10.4%, WP g by 11.9%, water productivity of biomass yield (WP b) by 6.2%, precipitation and irrigation water use efficiency (PIUE) by 10.4%, irrigation water use efficiency (IUE) by 12.0%, agronomic nitrogen use efficiency (ANUE) by 5.3%, NPFP by 10.6% and NI by 17.1%. Compared with I 0 , I 60 increased grain yield by 13.5%, WP g by 7.8%, ANUE by 5.7%, NPFP by 13.7% and NI by 27.9%. Increasing planting density improved soil water consumption, population nitrogen uptake, effective number of panicles per unit area, WP b , PIUE, ANUE, NUtE and total income. Grain yield, WP g , NPFP and NI reached the maximum values at MD under RF, because the presence of plastic film in RF reduced the number of planting rows and resulted in excessive planting density in the plant row at HD compared to F. In summary, the optimized planting density (360 ×104 plants ha−1) combined with ridge-furrow planting and supplementary irrigation is more desirable for balancing grain yield, water productivity, nitrogen use efficiency and economic benefit of winter wheat in the semi-humid and drought-prone region of northwest China. ● Planting pattern, supplementary irrigation and planting density had interactive effects on grain yield. ● Ridge-furrow planting and supplementary irrigation increased grain yield, water-nitrogen use efficiency and net income. ● Grain yield, water-nitrogen use efficiency and net income were maximal at medium density under ridge-furrow planting. ● Grain yield, water-nitrogen use efficiency and net benefit were balanced under RFMDI 60. [ABSTRACT FROM AUTHOR]