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In semiarid Kenya, field productivity of maize has been at a low integrity level due to insufficient use of rainwater use. From 2012 to 2013, an innovative ridge-furrow mulching system (RFMs) was tested using local maize ( Zea mays L.) hybrid, KCB in KARI-Katumani Farm, Kenya in long and short rainy seasons. Field experiments were conducted in a randomized complete block design with four treatments: 1) RFMs with transparent polyethylene film (RFT), 2) RFMs with black polyethylene film (RFB), 3) RFMs with grass straw mulching (RFS), and 4) RFMs without mulching (CK). Soil moisture & temperature, grain yield, water use and economic benefit were determined and analyzed. The results indicated that both RFT and RFB treatments significantly increased soil water storage amount in the depth of 0–60 cm. Grain yield and water use efficiency (WUE) in both treatments were increased by 66.5–349.9% and 72.9–382% respectively, compared with those of CK over two growing seasons. In addition, grain yield and WUE in RFS treatment were only increased by from 4.2–127.1% compared with those of CK. Particularly, two types of plastic films displayed different effects on modifying topsoil temperature. Transparent film mulching significantly increased topsoil temperature by 1.3 °C ( p < 0.05) higher than CK, to facilitate growth and grain formation in long (but cool) growing season. In contrast, black film mulching lowered soil temperature by 0.3 °C lower than CK in short (but warm) growing season, which led to better soil thermal balance. Overall, RFMs with film mulching could serve as an effective solution to increase maize productivity, and hence a promising strategy to cope with food security under climate change in semiarid Kenya. [ABSTRACT FROM AUTHOR]

The ridge-furrow rainfall harvesting system (RFRHS) is an in-situ rainfall collection and utilization technique that has been widely adopted in global arid and semiarid farming areas because of its significant benefits to soil water availability and crop yield. However, the integrated effects of different ridge-furrow configurations on rainwater collection and crop performance are still lacking. Using a specialized database drawn from field experiments in the Loess Plateau, we examined the regional effects of three typical ridge-furrow configurations, namely high (>1:1), uniform (=1:1), and low (<1:1) ridge-furrow ratios, on soil water storage, crop water use efficiency (WUE), and grain yield. The high ridge-furrow ratio achieved the greatest improvements in soil water storage than the other two ratios. Compared with traditional flat planting without ridge-furrow configuration, crop yield and WUE were significantly increased by 37.65%, 27.12%, 31.70%, and 47.70%, 30.00%, and 17.80% under high, uniform, and low ridge-furrow ratios, respectively. Improvements in crop yield and WUE due to the different ridge-furrow configurations were jointly affected by climate, soil organic matter, and fertilizer application. The mean annual precipitation of 600 mm and the mean annual temperature of 12 ℃ can be used as the threshold for selecting the ratio of ridge–furrow. An increase in soil organic matter gradually declined the increase in grain yield and WUE owing to the three ridge–furrow ratios, such that the maximum effect was found for the high ridge–furrow ratio. Among the three ratios, the improvements in crop yield and WUE were most notable when the application rates of nitrogen and phosphorus fertilizer were 100–200 kg ha−1 and 101–125 kg ha−1, respectively. This study examined the scientific basis of a ridge–furrow farming practice for enhancing rainfall use and crop WUE; thus, these results offer novel insights for the optimized design of a ridge–furrow ratio in dryland agroecosystems of the Loess Plateau by taking into account site-based climatic conditions, soil fertility, and fertilization input level. • Different ridge-furrow configurations have different effects on the improvements of soil water content, crop yield and WUE. • Improvements in grain yield and WUE were significantly affected by climate under three ridge-furrow ratios. • Soil physical and chemical factors and fertilizer application also influenced improvement effects of three ridge-furrow ratios. [ABSTRACT FROM AUTHOR]

• Plastic mulching significantly increased ET by 2.6% across the entire dataset. • Plastic mulching significantly increased SWS at 0−60 cm soil layer. • Soil water loss in deep soil was replenished during the fallow season. • Plastic mulching did not disrupt the annual equilibrium of soil water storage. • Crop yield and WUE were substantially improved under plastic mulching. In rain-fed semiarid areas, low soil water availability is a major challenge constraining crop productivity and agricultural sustainability. Soil surface mulching with plastic film has been widely used to improve soil water availability in the Loess Plateau of China. However, a systematic assessment on soil water balance dynamics under plastic mulching is still lacking. We conducted a meta-analysis on plastic mulching observations across the Loess Plateau to quantify the intensity of evapotranspiration (ET), spatiotemporal dynamics of soil water storage (SWS), and annual soil water balance in the plastic mulching systems. The results indicated that compared with non-mulching, plastic mulching significantly enhanced ET by 2.6% across the entire dataset. The magnitude of intensified ET was strongly associated with mulching pattern, mean annual precipitation and nitrogen application. Plastic mulching led to a significant increase in SWS by 8.4% at 0−60 cm soil layer, yet a decrease by 0.8% at 60−200 cm layer over the growing season, comparing with non-mulching. Importantly, an effective water recovery effect was observed at the deep soil layer under plastic mulching, as evidenced by the significantly greater SWS (+30%) over the fallow season, in comparison with that of non-mulching. Nitrogen input level and mean annual precipitation proved to be the most important factors in driving SWS. As a result, crop yield and water use efficiency were substantially improved under plastic mulching, and such enhancements were the most pronounced under full plastic mulching and lower annual mean precipitation. Increased vegetation growth due to plastic mulching can turn to impact soil water dynamics in both growing and fallow seasons, but it did not disrupt the annual equilibrium of SWS. Particularly, more precipitation storage at deep soil layer during the non-growing season appeared to fully offset the extra water loss by enhanced ET. Our findings provide critical insight into the success of plastic mulching farming practice regarding field productivity and soil water sustainability. [ABSTRACT FROM AUTHOR]

Precipitation is the major cause of crop yield variation in rainfed agriculture production on the Loess Plateau. As overfertilization is economically and environmentally undesirable, and crop yield and the resulting returns for N input are uncertain when rainfall variability is high, optimizing N management according to the precipitation of fallow season is vital for efficient crop water use and high yield in dryland/rainfed farming systems. Thus, this study established a reference range describing wheat cultivation year types based on fallow season precipitation over 37 years. We conducted an 8-year field experiment using seven different N input rates, to focus on soil water content and its vertical distribution in the 0–300 cm soil layers and to assess the relationship between soil water utilization and yield formation. The final objective was to evaluate how the optimal N input affects crop water consumption, with the aim of maximizing yields. Eight experimental years (2009–2017) were classified as dry and normal years (four of each), with optimum N application rates of 150 and 180 kg N ha−1, respectively. Compared with that used by farmers (210 kg N ha−1), optimum N input saved 26.8% and 12.3% of N fertilizer, increased grain yield by 5.0% and 5.2%, and improved crop water productivity (CWP) by 6.1% and 8.5% in dry and normal years, respectively. Optimized N inputs reduced soil water consumption before the jointing stage and increased the soil water available for grain yield production. Soil water depletion occurred from deeper soil layers with crop development, and soil water storage (SWS) at 80–240 and 200–300 cm depth played an important role in increasing spike number and grain filling, respectively. Furthermore, soil water conservation treatment (increasing rainwater storage via deep plowing at start of the summer fallow season) was unable to eliminate the variability in soil water storage at sowing, and as "drought at sowing" effects on yield were more adverse than "drought in growing season" effects in dryland systems, our results indicate that adjusting N fertilizer inputs based on summer rainfall variation could enhance wheat yield and CWP in the rainfed farming system. • N input was optimized to match year type based on fallow season precipitation. • Soil water storage in 80–300 cm depth was important for yield formation. • Optimized N input regulated water consumption during wheat development. • Optimizing N input for dryland wheat production was feasible and economical. [ABSTRACT FROM AUTHOR]

Plastic film residuals are increasingly remaining in cultivated lands. However, it is a critical issue how residual plastic type and thickness affect soil properties and crop yield. To address this issue, in situ landfill was conducted using thick polyethylene (PEt1), thin polyethylene (PEt2), thick biodegradable (BIOt1), thin biodegradable (BIOt2) residues, and CK (control) with no residues landfill in a semiarid maize field. The findings demonstrated that the impact of various treatments on soil characteristics and maize yield varied considerably. Soil water content decreased by 24.82% in PEt1 and 25.43% in PEt2, compared to BIOt1 and BIOt2, respectively. BIOt2 treatment increased soil bulk density by 1.31 g cm−3 and lowered soil porosity by 51.11%, respectively; it also elevated the silt/clay proportion by 49.42% relative to CK. In contrast, microaggregate composition in PEt2 was higher (43.02%). Moreover, BIOt2 lowered soil nitrate (NO 3 −) and ammonium (NH 4 +) content. Compared with other treatments, BIOt2 resulted in significantly higher soil total nitrogen (STN) and lower SOC/STN. Finally, BIOt2 exhibited the lowest water use efficiency (WUE) (20.57 kg ha−1 mm−1) and yield (6896 kg ha−1) among all the treatments. Therefore, BIO film residues exhibited detrimental impacts on soil quality and maize productivity compared to PE film ones. Considering film thickness, thin residual films more evidently influenced soil quality and maize productivity than thick film ones. [Display omitted] • BIO enhanced soil bulk density and lowered porosity, while thick PE residues didn't. • BIO significantly reduced SOC/STN, but thick PE residues exhibited a minor effect. • Relative to thick PE and CK, BIO residue lowered soil inorganic nitrogen. • WUE and yield decreased under BIO residues, while thick PE ones had a slight effect. • Thick PE and thin BIO residues had the least and most harmful impact, respectively. [ABSTRACT FROM AUTHOR]

Fallow tillage methods play a major role in improving soil water storage, water use efficiency and hence grain yield in winter wheat ( Triticum aestivum L.) cropping system in southeast Loess Plateau. However, the efficacy and stability of such methods need to be further validated in long-term field observation. From 2009–2015, a 7-year filed experiment was established in winter wheat fields at Wenxi Agriculture Station, semiarid southeast Loess Plateau. The objectives were to determine the responses of soil water storage, utilization and yield formation to three different tillage methods: including deep ploughing, subsoiling and no-tillage. Our results indicated that compared to no-tillage, the soil water storage (0–300 cm depth) was averagely increased by 7.8% and 6.0% during fallow season, 13.7% and 9.8% in growing season under deep ploughing and subsoiling respectively. Furthermore, the increasing magnitude in soil water due to deep ploughing and subsoiling was, on average, 10.1% and 5.5% higher in dry season than that in wet one. Improved soil water condition under deep ploughing and subsoiling significantly increased the ear number and grain yield by 20.2% and 15.9%, 30.8% and 25.8% respectively, but did not affect seed number and weight of thousand seed over the experimental seasons. Moreover, grain yields under deep ploughing and subsoiling were averagely increased by 35.2% and 24.8% in dry season, 28.7% and 20.6% in wet season respectively. Accordingly, water use efficiency and precipitation use efficiency were increased by 12.1% and 31.9% under deep ploughing, 11.1% and 25.0% under subsoiling respectively. Critically, we found that with an increase of 10% water storage efficiency during fallow season, ear number, grain yield and WUE could be increased by 0.2 million ha −1 , 241.1 kg ha −1 and 0.6 kg ha −1  mm −1 respectively. Our study clearly indicated that deep ploughing in fallow season should be adopted as a promising strategy to retain soil water availability and hence boost wheat productivity in semiarid southeast Loess Plateau. [ABSTRACT FROM AUTHOR]

Groundwater depletion has been a global concern due to unreasonable agricultural water managements. Identifying long-term impacts of crop rotation systems on hydrological parameters and crop yields can help to alleviate groundwater depletion. The Decision Support System for Agro-technology Transfer model was applied to simulate impacts of nine crop rotation systems (H1: continuous spring maize; H2: continuous potato; H3: continuous spring wheat; H4:potato-maize rotation; H5:maize-wheat rotation; H6: wheat-potato rotation; H7: two year fallow-maize rotation; H8: two year fallow-potato rotation; H9: two year fallow-wheat rotation) on crop evapotranspiration, percolation, yields, water use efficiency, net water use and groundwater table depth changes in Zhangjiakou, China from 1985 to 2018. The results showed DSSAT model performed well in simulating crop ET, yields (R2>0.9, RMSE<500 kg ha−1) and soil water content (R2>0.9 and RMSE<10.1 mm). The long-term two year fallow with one single crop rotation systems (H7 to H9) had lower total accumulative groundwater table depth changes (2.8–14.4 m) than others (12.7–52.3 m) from 1985 to 2018. Also, cropping rotation systems H7 to H9 obtained the lower annual average net water use (14–70 mm) compared to other cropping rotation systems (62–253 mm). The significant difference of net water use, crop yields, water use efficiency and accumulative groundwater table depth changes of nine different cropping systems indicated H4 and H8 is suitable in the study region. Our results is useful for selecting suitable cropping systems based on the water use for local farmers. [Display omitted] • Effects of cropping systems on groundwater were well simulated by DSSAT model. • Water-saving effect is different within different crop rotations. • Two year fallow with one single crop rotation alleviates groundwater decline. [ABSTRACT FROM AUTHOR]

Abstract: Effects of plastic mulching in ridges and furrows for varying durations on yield and water use efficiency (WUE) in potato were investigated in rainfed areas of north-western China in 2009 and 2010. The experiment comprised four mulched treatments (M50, M65, M80/85, and Mw – indicating plastic film mulch for 50, 65, and 80/85 d after sowing, and whole growth season, respectively – after which mulch in furrows was removed) and a non-mulched control. The results showed that film mulching warmed topsoil and increased topsoil water content. The daily mean topsoil temperature in mulched plots was 2.5–3.2°C higher than that in controls during the early growing season (sowing–emergence), the difference became less as the plant canopy grew; on some days later in the season, the difference was even negative (i.e. the topsoil temperature in mulched was lower than in control plots). Seedlings under mulching emerged 8.1–11.7 d earlier than those in controls due to the increased topsoil temperature and moisture in the early season. Mulching also prolonged the duration from seedling to maturity by 0.7–15.0 d and significantly increased plant height, leaf area index, and dry matter. Compared to non-mulched plots, yields in mulched plots increased by 33.9–92.5% and 62.9–77.8% in 2009 and 2010, respectively, and corresponding WUEs improved by 41.4–112.6% and 45.9–70.6%. Both tuber yield and WUE were highest in M65. The data indicate that mulching for about 65 d after sowing was ideal to optimize soil moisture and soil temperature and in turn to improve potato productivity and WUE in this semi-arid rainfed region. [Copyright &y& Elsevier]