Soil mulching can effectively modify the crop growth environment and increase crop productivity in rainfed agriculture. Accurate estimation of crop evapotranspiration (ET), especially its ...transpiration (T) component, is crucial for understanding the crop water use and predicting crop yield in agricultural ecosystems. Nevertheless, direct measurement of T in the field is often difficult, expensive, destructive and time-consuming. Daily rainfed maize T under four mulching methods (NM: non-mulching, SM: straw mulching, RPBF: plastic-mulched ridge with bare furrow, and RPSF: plastic-mulched ridge with straw-mulched furrow) was obtained from sap flow measurements over four maize growing seasons (2015–2018) in Northwest China. A modified Jarvis-Stewart model (MJS) and a support vector machine model optimized by the whale optimization algorithm (SVM-WOA) were further proposed to estimate daily maize T based on solar radiation (Rs), vapor pressure deficit (VPD), soil water content (SWC) and leaf area index (LAI), which were compared to the simple multiple linear regression model (MLR). The three models were calibrated using data obtained in 2015 and 2017, and validated using data from 2016 and 2018. The measured seasonal T under SM, RPBF and RPSF was increased by 6.9–19.1%, 12.1–31.3% and 15.3–36.7% compared to that under NM, respectively. The SVM-WOA model (R2 = 0.83–0.89, RMSE = 0.55–0.73 mm d−1, MAE = 0.42–0.53 mm d−1) was superior to the MJS model (R2 = 0.61–0.79, RMSE = 0.75–1.12 mm d−1, MAE = 0.58–0.88 mm d−1) during validation, both of which greatly outperformed the MLR model (R2 = 0.57–0.60, RMSE = 1.28–1.41 mm d−1, MAE = 0.99–1.09 mm d−1) under various mulching methods. The prediction accuracy of the SVM-WOA and MJS models was improved by 47–57% and 19–41% in terms of RMSE compared with that of the MLR model, respectively. Although the physically-based MJS model satisfactorily described the dynamics of rainfed maize T under various mulching methods, the blackbox-type SVM-WOA model was more suitable for estimating daily maize T after a careful calibration with adequate experimental data due to its advantage in modeling complex nonlinear relationships between T and its driving variables.
●Daily rainfed maize T under four mulching methods was measured during 2015–2018.●MLR, MJS and SVM-WOA models were compared for estimation of daily maize T.●SM, RPBF and RPSF increased T by 6.9–19.1%, 12.1–31.3% and 15.3–36.7% relative to NM.●SVM-WOA model produced the best T estimates, followed by MJS and MLR models.
•A combination of varying irrigation levels at different maize growth stages can help stabilizing the yield under uncertain supply of water.•Reducing the full irrigation supply by 20 % between V8 to ...maturity overall had the highest yield.•Impacts of water stress during the early to mid-vegetative stages can be compensated by supplying 80 % or 100 % irrigation during the later stages.•Water stress at certain growth stages could have positive impact on maize yield.
Uncertainty in the availability of water supply pose challenges to traditional irrigation approaches. Regulating the amount and time of irrigation at different crop growth stages could provide a solution to optimize the irrigation water amid drought periods. This study evaluated the effect of different deficit irrigation levels on maize (Zea mays L.) at several growth phases over two growing seasons (2012 and 2013) in Yangling, Shaanxi province of China. Total nine irrigation treatments incorporated three irrigation amount ratios, i.e., control irrigation (CK, 100 % of crop evapotranspiration), and 80 % and 60 % of control irrigation; named as T2–T9. Among the irrigation treatments, grain yield ranged from 6392 to 9362 kg ha–1 and seasonal water use efficiency (WUE) varied from 20.3 to 34.9 kg ha–1 mm–1, whereas the irrigation water use efficiency (IWUE) ranged between 32.0 and 58.1 kg ha–1 mm–1. T2 that received 80 % irrigation between V8 and R6 growth stage had overall higher yield than CK, and this was closely followed by T4 that received 80 % irrigation at growth phase V3-V8 and V11-Tasseling, full irrigation at V8-V11, and 60 % irrigation between Tasseling and Maturity. Due to near optimum growing season temperature in 2013, larger WUE was noted in comparison to 2012, that resulted 16 % larger yield with 10 % lesser ETc, on an average, whereas 2012 growing season had better IWUE because of 37.5 % smaller irrigation consumption. Maize grain yield in response to water stress (Ky, the yield response factor) was 0.66, suggesting that the environmental conditions of the study area favor the application of deficit irrigation. The maize yield response to reduced irrigation supply in this experiment indicated that regulated deficit irrigation might help growers to cope with decline in water availability during growing season.
Ring finger protein 6 (RNF6), a member of E3 ubiquitin ligases, plays a potential role as a tumour promoter in numerous carcinomas. However, the role and expression of RNF6 in breast cancer (BC) ...remains to be elucidated. The present study showed that RNF6 upregulation was detected in BC tissues and was associated with short survival in patients with BC. Multivariate analysis also revealed that RNF6 overexpression is an independent predictor for poor outcome of patients with BC. Furthermore, migration and metastasis assay indicated that RNF6 silencing significantly inhibited the invasion and migration of BC cells in vivo and in vitro, and RNF6 suppression decreased YES-associated protein (YAP) expression. RNF6 promoted the metastatic ability of BC cells via YAP. Mechanistically, RNF6 interacts with mammalian STE20-like protein kinase 1 (MST1), a key factor that regulates YAP, and promoted its ubiquitination and degradation. Additionally, RNF6 regulated YAP signalling by promoting ubiquitination and degradation of MST1 in BC. Taken together, these data may highlight a role of RNF6 in BC, which could serve as a valuable prognostic indicator and potential therapeutic target for patients with BC.
The number of apple (Malus pumila Mill.) orchards has increased substantially in hilly regions of the Loess Plateau of China, as a significant element of the large-scale ‘Grain for Green’ ecological ...rehabilitation program that aims to conserve soil and water while improving the regions economic prospects. However, the long-term effects of the orchard expansion and the adaptive responses of apple trees to drought are not known. Thus, using a space-for-time substitution approach, we investigated plant-available water and fine-root distribution in the 0–8 m soil profile in apple orchards of various ages in a dry year (2015, 392 mm rainfall) and the following year with normal precipitation (2016, 500 mm rainfall). We found that plant-available water gradually decreased with stand age in the dry year, but increased in the normal year, especially in the 0–2 m soil layer. Fine root (<2 mm diameter) distribution and biomass increased with stand age and decreased with increasing soil depth in all treatment plots, predominantly in the 0–2 m layer. In all treatment plots, most of the soil layers in the deep soil (>2 m) had soil moisture storage deficit. In the dry year (2015), the apple trees increased both the average depth (D50 and D95 values) and biomass of their fine-root systems in response to water stress, relative to the normal year (2016). Thus, the apple trees extracted water primarily from the shallow (<2 m) layers in the normal year, but from deeper soil layers in the dry year, to sustain growth. The results of this study will help to guide land and agricultural water management in rainfed apple orchards in hilly regions of the Loess Plateau and similar dryland regions.
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•Stand ages and rainfall strongly affect the water balance and distribution by affecting roots' water uptake patterns.•There was positive adaptive response of apple trees in areas with a dry climate to water shortage.•The root systems could switch between shallow and deep-water sources, depending on availability.•The trees apparently extracted water primarily from shallow (<2 m) layers, during the ‘normal’ year.•The trees mainly sustained their growth by taking up deeper (>2 m) water in the drier year.
•High pressure processing of pre-rigor muscles modified myosin physicochemical traits.•Myosin extracted from high-pressure treated muscles had different gelation behaviors.•Denaturation rate of ...myosin during heating was crucial for water-holding capacity.•Moderate high-pressure treatments of pre-rigor muscle favored gelation of myosin.
Myosin was extracted immediately after high-pressure treatment (HP, 100–300MPa for 15 or 180s) to pre-rigor rabbit muscles (PRRMs) for evaluating the influences of HP-treatment on gel properties, using untreated muscles as Controls. Assessment of myosin yields, water-holding capacity (WHC), water mobility and distribution demonstrated that HP modified myosin before its extraction. Myosin gels subjected to HP at 100MPa 180s and 200MPa 15s had enhanced WHC compared with Controls. Also, the highest proportion of immobile-water was observed in myosin gels treated at 200MPa for 15s. HP-treatment of PRRMs affected their physicochemical properties as evidenced by alterations in tertiary, secondary conformations and rheological properties during subsequent heating. These modifications appear to induce various degrees of exposure of hydrophobic and sulfhydryl groups, resulting in different gelation rates. These alterations partly explain the various gel qualities obtained and indicate the potential of HP for pre-rigor muscles.
Soybean (Glycine max L. Merr) is an important crop around the world. Adaptive soil and crop managements are crucial for improving rainfed soybean productivity and resource use efficiency under ...changing climate. The ridge-furrow plastic mulching system was applied for the first time to rainfed soybean, and its combined effects with dense planting and reduced nitrogen (N) on soil water and temperature, soybean growth, yield, water use efficiency (WUE) and economic return were explored in 2019 and 2020 in a semi-humid drought-prone region of China. There were two planting modes: flat cultivation with no mulching and ridge-furrow cultivation with plastic film mulching on the ridge, and four crop management practices: sparse planting (160,000 plants ha−1) with reduced N rate (30 kg N ha−1), sparse planting with high N rate (60 kg N ha−1), dense planting (320,000 plants ha−1) with reduced N rate (30 kg N ha−1) and dense planting with high N rate (60 kg N ha−1). Compared with flat cultivation with no mulching, ridge-furrow plastic mulching significantly increased average surface soil water (0–20 cm) by 6.7% and soil temperature (by 0.5–1.5 ℃ at 10–25 cm depths), which promoted leaf area index (LAI) by 9.0%, total chlorophyll content (Chl) by 10.4%, net photosynthesis rate (Pn) by 1.6%, resulting in increases in soybean yield, WUE and net income (NI) by 11.1%, 10.7% and 8.6%, respectively. Compared with sparse planting, dense planting decreased average Pn by 7.5%, aboveground biomass per plant by 15.7%, pods per plant by 29.9% and hundred-grain weight by 3.8%; however, it improved LAI by 15.7%, soybean yield by 32.3%, WUE by 28.8% and NI by 44.3%. Compared with reduced N rate, high N rate improved average LAI by 14.0%, Chl by 11.1% and Pn by 4.2%, resulting in increases in soybean yield by 10.1%, WUE by 9.7% but NI by only 2.4%. Compared with the traditional flat cultivation with no mulching and sparse planting with high N rate, ridge-furrow plastic mulching and dense planting with reduced or high N rate significantly improved soybean yield (by 25.6% or 38.8%) and WUE (by 23.8% or 38.0%) (P < 0.05), but the former produced greater net income (12,749.7 CNY ha−1) than the latter (12,433.4 CNY ha−1) with 50% less N input. In conclusion, ridge-furrow plastic mulching and dense planting with reduced N rate is a more promising practice to trade off yield, water productivity, economic return and environmental benefit of rainfed soybean.
•Ridge-furrow plastic mulching was applied for the first time to rainfed soybean.•Ridge-furrow plastic mulching improved soil hydrothermal condition.•Dense planting with low N decreased yield per plant, but improved population yield.•Ridge-furrow plastic mulching and dense planting with low N improved soybean yield.
Agricultural intensification has turned the drylands-dominated Loess Plateau (LOP) of China into the world’s largest apple production area, which has greatly contributed to increasing farmer’s income ...and reducing rural poverty in the past two decades. However, substantial environmental trade-offs are evident, including (i) severe deep soil desiccation, which lowers resistance to extreme droughts; (ii) low soil organic carbon sequestration, which undermines apple tree’s ability to mitigate climate change; (iii) high soil erodibility, which increases the risks for orchards suffering serious erosion; and (iv) severe residual nitrate pollution, which threatens drinking water and planetary health. We propose a conceptual framework for addressing those environmental externalities, which will incorporate a nexus of scientists and technicians, policymakers, social enterprises, and smallholder farmers (SPES) to emphasize good governance, green-production technologies (GPTs), and collaboration as the route toward sustainable intensification and the realization of SDG 1 (alleviation of rural poverty), SDG 6 (reduction of soil and water pollution), SDG 13 (provision of important carbon sinks), and SDG 15 (positive water cycling and soil and water conservation). This framework may also offer insight into the sustainable development of orchards in dryland areas with similar environmental issues.
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•Great economic-environmental trade-off exists in dryland apple orchards in China.•Apple orchards development greatly improves farmer’s income and reduces poverty.•Apple orchards cause soil desiccation, low soil C sequestration and nitrate pollution.•A conceptual framework is proposed to realize SI and SDGs of dryland orchards.
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