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In dryland areas, integrating biochar soil amendment with in situ rainwater harvesting systems may decrease soil erosion, improve soil quality, and increase crop productivity and yield. This study was conducted to investigate the effect of maize straw biochar amendment and ridge‐furrow rainwater harvesting systems on run‐off, sediment yield and the physico‐chemical properties of a Calcic Cambisol soil in semiarid areas. The experiment was conducted on alfalfa (Medicago sativa) production land at the Anjiagou Catchment experimental station in Gansu province, China. The experimental layout was a split‐plot design with three replications. Biochar was applied at a rate of 0 and 30 t ha−1, respectively. The tillage treatments were flat planting, open‐ridging, and tied‐ridging (TR). Overall, the integration of maize straw biochar with TR decreased soil bulk density at 0–40 cm depth. Biochar application reduced run‐off by 37.8% and soil loss by 55.5% during alfalfa‐growing seasons compared to the control. In general, biochar addition increased soil total potassium, but the same effect was not observed for soil pH, total nitrogen, total phosphorus, and available phosphorus. These findings demonstrate the potential of integrating maize straw biochar and tillage systems to reduce soil erosion and improve soil quality for rainfed crop production in semiarid areas. Further studies on the effect of biochar‐tillage system interaction are warranted to improve soil conditions for plant growth and increase crop yield in dryland areas. [ABSTRACT FROM AUTHOR]

Purpose: Erratic climatic conditions and poor intrinsic soil properties are major challenges constraining agricultural sustainability, resilience, and food security in the Loess Plateau in China. Thus, it is necessary to explore ridge-furrow rainwater harvesting with organic mulches to improve soil physical properties and maintain sustainable agricultural production. Materials and methods: A consecutive 5-year field experiment was conducted in a randomized block design with ten treatments (three biochar application rates (0, 30, and 60 t ha−1) × three ridge widths (30, 45, and 60 cm) + flat planting without biochar (FP) as a control). Results: Ridges compacted with biochar-soil mixture reduced bulk density and soil solid-phase ratio and increased total and capillary porosity, soil gas-phase ratio, and aggregate stability. Compared to FP, available water content in ridges compacted with biochar-soil mixture increased by 0.5–9.0% at furrow bottoms and 1.4–22.9% at ridge tops. Annual alfalfa fodder yield for MCS30, MCS45, MCS60, SMB30, SMB45, SMB60, DMB30, DMB45, and DMB60 (MCS, SMB, and DMB were abbreviations for ridges compacted with biochar-soil mixture at biochar application rate of 0, 30, and 60 t ha−1, respectively, while subscript numbers 30, 45, and 60 referred to ridge widths) increased by 9.4%, 9.4%, 6.9%, 29.5%, 24.9%, 12.5%, 21.3%, 16.2%, and 6.1%, respectively, over 5 years. Conclusions: Ridges compacted with biochar-soil mixture improved soil physical properties. Suitable biochar application rate was 30 t ha−1 and optimum ridge width was 30 cm for alfalfa production in ridge-furrow rainwater harvesting with biochar application. [ABSTRACT FROM AUTHOR]

Purpose: Environmentally friendly mulching material and appropriate tillage practice are needed to solve plastic film residues in agricultural production in ridge-furrow rainwater harvesting technology (RFRHT) in the Loess Plateau in China. Materials and methods: A field experiment in randomized block design was conducted to (1) investigate the runoff coefficient for three ridge widths (30, 45, and 60 cm) using three ridge mulching materials (ridges compacted with soil (RCS), maize straw biochar-soil mixture (SBM), and cow dung biochar-soil mixture (DBM)); (2) the effects of three ridge widths using three ridge mulching materials on soil moisture, temperature, nutrients, fodder yield, quality, and water use efficiency (WUE) of sainfoin and conventional flat planting (FP) as a control, during two consecutive sainfoin-growing years: 2017 and 2018. Results: The predicted runoff coefficient for RCS30, RCS45, RCS60, SBM30, SBM45, SBM60, DBM30, DBM45, and DBM60 (subscripts 30, 45, and 60 referred to ridge widths) was 0.31, 0.33, 0.34, 0.26, 0.30, 0.31, 0.22, 0.24, and 0.25, respectively, over 2 years. DBM had a higher concentration of total nitrogen and organic matter compared to SBM, while SBM had a higher concentration of Olsen phosphorus and available potassium compared to DBM. The higher runoff coefficient and soil moisture in SBM led to higher fodder yield, WUE, and condensed tannin content of sainfoin, compared to DBM. Compared to FP, in RCS, fodder yield and WUE of sainfoin decreased by 8.8–17.8% and 0.6–2.6 kg ha−1 mm−1, respectively. Condensed tannins concentration of sainfoin for RCS, SBM, and DBM increased by 4.1 −9.0%, 11.4 −21.8%, and 9.4 −15.2%, respectively. Fodder yield in SBM and DBM increased by 14.3 −19.5% and 7.1 −10.0%, respectively, while WUE in SBM and DBM increased by 6.7 −8.5 and 4.7 −5.5 kg ha−1 mm−1. Conclusion: Ridges compacted with biochar-soil mixture, especially with maize straw biochar-soil mixture, increased fodder yield, WUE, and condensed tannin content of sainfoin. The optimum ridge width in SBM and DBM for sainfoin production was 46–49 and 41 cm, respectively. [ABSTRACT FROM AUTHOR]

Purpose: On a global scale, water resources are under intense stress due to climate change. It is, therefore, crucial to understand how in situ water harvesting techniques and the addition of soil organic amendments such as biochar affect soil properties and productivity of alfalfa (Medicago sativa L.) to inform wider adoption by farmers. Methods: To contribute to this research area, an experiment was conducted at the Anjiagou Catchment experimental station during the 2020 to 2021 alfalfa growing seasons. The experimental design was a split-plot design with three replications. The main treatment was maize straw biochar, and the sub-treatment was ridge-furrow rainwater harvesting. The biochar treatments were 30 t ha−1 and 0 t ha−1, and the rainwater harvesting methods were flat planting (FP), tied-ridging (TR), and open-ridging (OR). Results: In 2020, soil temperature in the TR treatment decreased by 6.54 and by 4.08% for the OR treatment compared with the FP. In 2021, soil temperature decreased by 3.87 and 0.87% in the TR and OR, respectively, compared with the FP. In general, the integration of rainwater harvesting systems and maize straw biochar amendment significantly (p < 0.05) increased alfalfa fodder yield during the 2-year growing seasons investigated. Mean soil desiccation increased by 55.16% in the no-biochar–amended treatment compared to 52.58% for the biochar-amended soils. Overall, the highest net economic benefit throughout the 2 years of alfalfa cultivation was recorded in the TR and OR treatments with maize straw biochar addition. Conclusion: In both experimental years, ridge-furrow rainwater harvesting-planting with maize straw biochar produced the highest alfalfa fodder yield than the FP treatment and the no-biochar–amended soil. An important contribution of this work to smallholder forage farming is the evidence demonstrating the positive effects of maize straw biochar in ridge-furrow rainwater harvesting system on alfalfa fodder yield, water productivity, and economic benefit in rain-fed agriculture. [ABSTRACT FROM AUTHOR]

Purpose: Drought and soil erosion are significant environmental challenges to agricultural production in the Loess Plateau of China. We hypothesized that ridge-furrow rainwater-harvesting, especially tied-ridge-furrow rainwater-harvesting, with biochar application would increase soil moisture, temperature, and alfalfa fodder yield, and reduce runoff and sediment yield. Materials and methods: A split-plot design experiment was conducted to determine the effects of biochar application patterns (biochar application pattern and no biochar application pattern) and tillage practices (tied-ridging, open-ridging, and flat-planting) on soil temperature, moisture, runoff, sediment yield, fodder yield, and water use efficiency (WUE) of alfalfa during two consecutive alfalfa-growing years: 2019 and 2020. Results: Biochar application decreased runoff, sediment yield, soil temperature, and increased soil water storage, compared to no biochar application. Open-ridging and tied-ridging significantly increased soil water storage, fodder yield, WUE of alfalfa, and decreased runoff and sediment yield, compared to flat-planting. Compared to no biochar application, soil water storage for biochar application increased by 34.51 mm during alfalfa growing season over two years. The mean runoff and sediment yield for no biochar application were 1.48–1.69 and 1.94–2.25 times greater than that for biochar application, respectively. Compared to flat-planting, the mean decrease of runoff and sediment yield was 27.4–31.9% and 60.1–64.7%, respectively, for open-ridging, while it was 37.1–55.2% and 71.8–82.4% for tied-ridging. The mean increase of soil water storage, fodder yield, and WUE of alfalfa for open-ridging was 39.5–52.1 mm, 26.2–31.7%, and 10.07–14.86 kg ha−1 mm−1, respectively, while it for tied-ridging was 31.2–60.5 mm, 26.5–35.2%, and 12.14–16.55 kg ha−1 mm−1 over two years. Conclusions: Tied-ridge-furrow rainwater-harvesting with biochar application is a potentially effective adaptation technology that could control soil erosion and increase alfalfa fodder yield in semiarid regions. [ABSTRACT FROM AUTHOR]

Agriculture production in study areas benefits from the use of ridge‐furrow rainwater harvesting (RFRH) to supplement rainfall in the absence of irrigation from imported sources. However, it is necessary to select suitable fodder plants for use with RFRH in this climate. In this paper, 10 treatments (3 ridge widths × 3 ridge‐mulching materials + flat planting [FP] as control) in a complete random design were applied in a 3‐yr field experiment for alfalfa (Medicago sativa L.) and oat (Avena sativa L.) production, respectively. Ridges mulched with plastic film (PF) and ridges mulched with biodegradable film (BF) had positive effects on fodder, grain yields, and water use efficiency (WUE), but ridges with manually compacted soil (MCS) had a negative effect on yield and WUE in the most cases. Fodder, grain yields, and WUE decreased as ridge width increased. For oats, the decrease of WUE of MCS was 1.31 kg ha−1 mm−1, but the increase of WUE of BF and PF was 0.83 and 1.25 kg ha−1 mm−1, respectively, compared with that of FP over 3 yr. For alfalfa, the increase of WUE of MCS, BF, and PF was, respectively, 0.22, 5.62, and 6.33 kg ha−1 mm−1. The RFRH systems, especially PF and BF, produced oat and alfalfa fodders with increased crude protein content and decreased acid and neutral detergent fiber content. The average alfalfa fodder yield was 1.37 times greater than that of oats, whereas the average WUE of alfalfa was 2.62 times greater than that of oats. Alfalfa fodder contained higher crude proteins and lower neutral detergent fiber content than oat fodder and had similar acid detergent fiber. It is more economic to harvest oat fodder than to harvest oat grain, and it is more economic to produce alfalfa than to produce oats. [ABSTRACT FROM AUTHOR]

Ridge-furrow rainwater harvesting (RFRH) with mulch offers farmers means to address drought, water loss, and soil erosion in arid and semiarid regions. Plastic film is widely used as a mulching material for RFRH; however, contamination of arable lands by its residual is a serious concern. We compared various mulches, including a biodegradable film for RFRH planted with sainfoin (Onobrychis viciifolia). A field study was conducted to (1) estimate runoff efficiency from three ridge widths using three different mulching materials; and (2) assess the effects of ridge widths and mulching materials on topsoil temperature, soil water storage, fodder yield, fodder nutrition, and water use efficiency (WUE) of RFRH planted with sainfoin, during 2015 and 2016. The predicted runoff efficiency for MCS30, MCS45, MCS60, BF30, BF45, BF60, PF30, PF45, and PF60 [MCS, BF, and PF are abbreviations for ridges with manually compacted soil, mulched with biodegradable film and with plastic film, respectively, subscripts 30, 45, and 60 refer to ridge widths (cm) all with 60 cm furrow width] was 9.9%, 22.2%, 24.7%, 85.3%, 88.8%, 92.7%, 85.9%, 89.7%, and 93.3%, respectively. The practice of RFRH, especially BF and PF, resulted in increased topsoil temperature at ridge tops and increased soil water content at furrow bottoms but decreased topsoil temperature at furrow bottoms. MCS decreased actual fodder yield, but BF and PF increased actual fodder yield. Compared to flat planting (FP), the decrease of actual fodder yield for MCS30, MCS45, and MCS60 was 7%, 15%, and 18%, respectively, for 2015 and 2016, but the increase of actual fodder yield for BF30, BF45, BF60, PF30, PF45, and PF60 was 10%, 8%, 6%, 15%, 13%, and 8%, respectively. Mean WUE for MCS, BF, and PF was 1.58, 1.64, and 1.70 times greater than that for FP, respectively. High soil water content and high soil temperature in RFRH, especially for BF and PF, resulted in increased crude protein and phosphorus content of the fodder produced but resulted in decreased acid detergent fiber and neutral detergent fiber content of fodder. Mean crude protein content for BF and PF was 1.25 and 1.30 times greater than that for FP, respectively, whereas phosphorus content for BF and PF was 1.37 and 1.32 times greater than that for FP. The optimum ridge width for BF was 35–36 cm, whereas for PF, it was 36–42 cm. The RFRH design should conserve water and improve fodder yields and quality. [ABSTRACT FROM AUTHOR]

Soil desiccation is a major challenge faced by subsistence farmers growing alfalfa (Medicago sativa L) in consecutive cultivation in semiarid regions. We hypothesized that alfalfa fodder yield would increase with the length of growing season, growing degree-days, and rainfall. A field experiment was conducted on alfalfa production from 2012 to 2016 to 1) determine the response of fodder yield to rainfall, the length of growing season, and accumulated growing degree day (AGDD) in different growing-cutting stage (GCS)s; 2) obtain the suitable mulching material and the optimum ridge width for ridges with manually compacted soil (MCS), mulched with bio-degradable film (BF), and plastic film (PF). There were 10 treatments (3 ridge widths × 3 ridge-mulching materials + flat planting (FP) as control) with three replications laid in a randomized block design. The ratio of the first GCS to the second GCS in fodder yield ranged from 1.10 to 4.55, which was similar to the ratio of the first GCS to the third GCS in fodder yield ranged from 1.14 to 4.59, although rainfall, the length of growing season, and AGDD were different during the two or three GCSs. The highest fodder yield was obtained from the first GCS in one year and reached the highest level in the second growing year, and maintained a similar level in the subsequent years, although rainfall, the length of growing season, and AGDD varied during the five year periods. Fodder yield was affected by both the rainfall in the GCS and the available soil moisture prior to the GCS. Compared to FP, the increase of evapotranspiration for MCS, BF, and PF was 11, 61, and 63 mm, respectively. Fodder yield for BF and PF increased by 28% and 33%, respectively. Fodder yield for MCS maintained the same level as that for FP. Evapotranspiration increased and fodder yield decreased as ridge width increased. The optimum ridge width for MCS, BF, and PF was 29, 39, and 37 cm, respectively, across five years. Future study should focus on alfalfa-crop rotation to mitigate soil desiccation after alfalfa consecutively production. • High rainfall, growing season length and temperature did not mean high alfalfa fodder yield. • Soil moisture prior to growing-cutting stage and rainfall in the stage had impact on alfalfa fodder yield. • Rainfall had higher effects on alfalfa fodder yield than actual evapotranspiration. • Highest fodder yield was obtained in first growing-cutting stage and reached highest level in second stand year. • Optimum ridge width for ridge compacted with soil, biodegradable and plastic film was 29, 39 and 37 cm, respectively. [ABSTRACT FROM AUTHOR]

• The silage yield, grain yield, biomass yield and WUE of maize were 1.75, 1.87, 1.82 and 1.76 times, respectively, greater than those of sorghum. • Biodegradable film and maize straw mulching did not change the total water loss by evaporation and transpiration. • Maize straw mulching provided a lower increase in grain yield compared with biodegradable film mulching. • Liquid film mulching did not significantly increase crop yields and water use efficiency compared with no mulching. In order to select environmentally friendly mulching materials and to increase rainwater utilization in a semiarid region of Northwest China, a field experiment was conducted using a randomized complete design to determine effects of three furrow-mulching materials (liquid film (LF), maize straw (MS) and biodegradable film (BF)) on soil temperature, moisture, evapotranspiration (ET), crop (maize and sorghum) yields and water use efficiency (WUE) with no-mulching (NM) as a control, during three consecutive crop growing seasons in years 2013-2015. Silage, grain, and biomass yields and WUE for maize were 1.75, 1.87, 1.82 and 1.76 times greater than corresponding yields and WUE for sorghum during the study period. BF increased topsoil temperature and soil water storage, while MS decreased topsoil temperature but increased soil water storage. Compared with NM, the increase in average topsoil temperature at the furrow bottoms of BF was 1.05–1.37 ºC during the growing seasons for maize, while it was 1.07–1.25 ºC during the growing seasons for sorghum. During the growing seasons, the decrease in topsoil temperature at the furrow bottoms for MS was 1.22–1.81 ºC for maize, while it was 1.34–1.59 ºC for sorghum. BF and MS decreased furrow soil evaporation but increased crop transpiration, while they did not shift the total water loss from ET. BF resulted in high soil temperature and moisture, increased crop yields, and WUE. Although low temperatures impaired emergence and crop development, high soil moisture increased crop yields and WUE with MS. Compared with NM, BF treatments resulted in increased mean silage, mean grain and mean biomass yields for maize of 17.0%, 17.7% and 13.7%, respectively, while corresponding yields for sorghum increased by 12.9%, 17.0% and 11.7%, respectively. The mean silage, grain, and biomass yields for maize with MS increased by 9.3%, 12.1% and 8.0 %, respectively, while corresponding yields for sorghum increased by 5.6%, 14.3% and 6.7%, respectively. Mean WUEs for maize and sorghum with BF significantly increased by 4.8 and 2.6 kg ha−1mm−1, respectively, while those values with MS significantly increased by 3.8 and 2.8 kg ha−1mm−1. MS provided a lower increase (12.1 %–14.3 %) in grain yields compared with BF (17.0 %-17.7%) in the study. LF had similar soil temperature and water moisture as with no mulching, and did not significantly increase either crop yields or WUE. [ABSTRACT FROM AUTHOR]

Drought, water loss and soil erosion are the main factors restricting grain production and economic development in the semiarid hill areas of Loess Plateau, China. A field experiment was conducted to determine the effects of different tillage systems (open-ridging and tied-ridging) on soil water moisture, runoff, sediment yield, fodder yield and water use efficiency (WUE) on 2 slopes (5° and 10°), using traditional planting (without ridges and furrows) as a control, during 2 consecutive alfalfa growing years: 2015 and 2016. Results indicated that the benefits of fodder yield and WUE increase from tillage system were more effective than the benefits from slope gradient on slight sloping land. Open-ridging and tied-ridging decreased runoff and sediment transport and increased soil moisture, fodder yield and WUE of alfalfa. The decrease of sediment for open-ridging and tied-ridging was 85.1% and 88.4%, respectively, for slopes of 5°, while it was 83.9% and 89.0% for slopes of 10°. Only 7–10% rainfall events produced runoff and 4–6% rainfall events produced sediment. The mean runoff efficiency for traditional planting, open-ridging and tied-ridging was 11.6%, 9.1% and 6.7%, respectively, for slopes of 5°, while it was 13.4%, 10.0% and 7.8% for slopes of 10°, over 2 years. Increase of fodder yields for open-ridging and tied-ridging was 34.6% and 19.8%, respectively, for slopes of 5°, while it was 32.7% and 20.6% for slopes of 10°, over 2 years. The average WUE for open-ridging and tied-ridging was respectively 1.96 and 1.85 times greater than that for traditional planting, for slopes of 5°, while it was 1.88 and 1.77 times greater than that for traditional planting, for slopes of 10°, over 2 years. The mean runoff and sediment for slopes of 10° was 1.14–1.16 and 1.19–1.57 times that for slopes of 5°, respectively. The differences of fodder yield and WUE between slopes of 5° and slopes of 10° were not significant. Tied-ridging rainwater harvesting offered particular effects on water and soil conservation, while open-ridging offered particular effects on fodder yields and WUE enhancement during the first and the second growing seasons. [ABSTRACT FROM AUTHOR]

Ridge-furrow rainwater-harvesting (RFRH) has emerged as an effective technology to mitigate drought stress, control soil erosion, and increase crop yield in semiarid regions of China. However, the use of plastic film mulch in RFRH makes this technology impractical. A field experiment was conducted for three consecutive years in a randomized complete block design to determine 1) the runoff coefficient for ridges compacted with soil mixed with two types of biochar (rice straw biochar and cow dung biochar) at two application rates (single application rate i.e., 3 × 104 kg ha−1; and double application rate i.e., 6 × 104 kg ha−1; and 2) the effects of the ridges compacted with soil mixed with two types of biochar at two application rates on soil physico-chemical properties, economic benefit, fodder yield and water use efficiency (WUE) of alfalfa, and ridges compacted with soil (no biochar) as control. The average runoff coefficient for NB, SRSB, DRSB, SCDB, and DCDB (NB, SRSB, DRSB, SCDB, and DCDB were ridges compacted with soil, compacted with soil mixed with single rice straw biochar application, double rice straw biochar application, single cow dung biochar application, and double cow dung biochar application, respectively) over these three years was 31%, 28%, 27%, 22%, and 21%, respectively. Ridges compacted with soil-biochar crust had lower runoff coefficients, soil water storage, net income, and higher soil nutrients, when compared to ridges compacted with soil. The topsoil temperature at ridge tops was affected by the ridges compacted with soil-biochar crust, but the topsoil temperature at furrow bottoms was not affected. Compared to ridges compacted with soil mixed with cow dung biochar, ridges compacted with soil mixed with rice straw biochar had lower soil nutrients, and higher soil water storage resulting in higher fodder yield and WUE of alfalfa. With runoff, the nutrients in biochar flowed from ridges to furrows, becoming usable for plants. Ridges compacted with soil-biochar crust increased topsoil nutrients, especially soil organic matter ranging from 15% to 34%, resulting in high fodder yield and WUE of alfalfa. Compared to NB, annual fodder yield for SRSB, DRSB, SCDB, and DCDB increased by 9.0%, 5.9%, 4.4%, and 3.8%, respectively, over three years, while WUE for the same treatments increased by 2.81, 1.95, 0.65, and 0.45 kg ha−1 mm−1. Rice straw biochar at an application rate of 3 × 104 kg ha−1 was found to be suitable type of biochar for increase in fodder yield and WUE of alfalfa in RFRH. Future studies should be conducted in the form of long-term field study to determine economic benefits of biochar application. • Ridges compacted with soil-biochar had low runoff coefficient, soil moisture, and high soil nutrients. • High topsoil nutrients, especially organic matter, resulted in high fodder yield and WUE of alfalfa. • As biochar application rate increased, runoff coefficient and soil moisture decreased, while soil nutrients increased. • Rice straw biochar resulted in low soil nutrients and high soil moisture, compared to cow dung biochar. • Rice straw biochar (3 × 104 kg ha−1) was suitable form in ridge-furrow rainwater-harvesting. [ABSTRACT FROM AUTHOR]