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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: 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]

Water scarcity and water-related soil erosion are severely exacerbated by inappropriate human activities and global climate change. Hence, to find a suitable technology to mitigate drought and soil erosion, three consecutive field experiments were conducted to explore the impact of ridge-furrow cropping with biochar amendment on soil water storage, runoff, sediment yield, soil nutrient losses, alfalfa (Medicago sativa L) fodder yield, crop water productivity (WP c), and economic benefit from 2019 to 2021. This experiment was conducted in a split-plot design, taking biochar amendment patterns (no biochar amendment and biochar amendment at a rate of 3× 104 kg ha−1) as a main plot and ridge-furrow technologies (traditional planting, open-ridging, and tied-ridging) as a split-plot. The combination of biochar amendment with ridge-furrow technology, especially tied-ridging technology, increased soil water storage, and captured runoff, sediment, and related soil nutrient losses, consequently increasing alfalfa fodder yield, WP c , and income. During this study, compared to traditional planting, open-ridging depicted an increase in soil water storage by a range of 9.8–39.6 mm, an alfalfa fodder yield boost ranging from 9.8% to 38.6%, and a WP c increase ranging from 0.1 to 16.5 kg ha−1 mm−1. On the other hand, tied-ridging showed greater improvements with soil water storage increasing by 29.1–65.1 mm, alfalfa fodder yield growing by 11.6–44.4%, and WP c advancing by 0.9–17.5 kg ha−1 mm−1. The mean decrease in runoff, sediment, and nutrients (total nitrogen, total phosphorus, and organic matter) loss for open-ridging was 17.9%-37.7%, 46.4%-75.5%, and 40.4%-75.3%, respectively, while for tied-ridging, it was 22.3%-55.5%, 62.1%-87.6%, and 49.0%-87.3%, respectively. Compared to no biochar amendment, soil water storage, alfalfa fodder yield, and WP c for biochar amendment increased by 9.1%-20.4%, 5.8%-52.7%, and 4.6–7.8 kg ha−1 mm−1, respectively, while runoff, sediment, and nutrients loss for biochar amendment decreased by 32.2%-40.9%, 25.5%-55.5%, and 35.9%-53.3%, respectively. Structural equation modeling analysis indicated that the significant direct effect of biochar amendment and ridge-furrow technology on WP c was 0.20 and 0.62, respectively, whereas the significant direct effect of runoff and actual crop evapotranspiration on alfalfa fodder yield was −0.40 and 0.94, respectively. Tied-ridge cropping combined with biochar addition was a highly suggested approach for addressing soil erosion and enhancing alfalfa fodder yields in the Loess Plateau in China. This technology could mitigate soil water scarcity and soil erosion, and give farmers the confidence to invest in this technology in dryland regions. • Ridge-furrow technology with biochar amendment reduced soil erosion. • Ridge-furrow technology with biochar amendment increased crop yield. • Biochar amendment and ridge-furrow technology had a direct effect on water use efficiency. • Runoff and evapotranspiration had a direct effect on alfalfa fodder yield. • Tied-ridge cropping with biochar amendment was recommended. [ABSTRACT FROM AUTHOR]

Background. Loss of organic matter and mineral nutrients to soil erosion in rain- fed agriculture is a serious problem globally, especially in China’s Loess Plateau. As a result, increasing rainwater usage efficiency by tied-ridge-furrow rainwater harvesting with biochar is expected to improve agricultural productivity. Nonetheless, with limited knowledge on tied-ridge-furrow rainwater harvesting with biochar, small-scale farmers face the challenge of adoption, thus, the rationale for this study. Materials and methods. A field experiment was conducted to determine the influence of open-ridging (OR) and tied-ridging (TR) with bio-degradable film on ridges and biochar in furrows on runoff, sediment losses, soil moisture, fodder yield, and water use efficiency (WUE) on sloped land, using flat planting (FP) without ridges and furrows as control, during alfalfa-growing year (2020). Results. Runoff in flat planting (30%), open ridging (45%), and tied ridging (52%) were decreased with biochar to the extent where sediment was decreased in flat planting (33%), open ridging (43%), and tied ridging (44%) as well. The mean runoff efficiency was lower in flat planting (31%), open ridging (45%), and tied ridging (50%) in biochar plots compared to no-biochar plots. In biochar and no-biochar plots, soil temperature on ridges of TR was higher than that on OR, which was higher than FP during alfalfa growing season. Soil temperature in furrows during alfalfa growing season in biochar and no-biochar plots were in the order FP > OR > TR. Mean soil water storage for FP, OR, and TR, in biochar plots was higher than in no-biochar plots. This indicates biochar has a beneficial impact on open riding. Total annual net fodder yield (NFY) was significantly (p = 0.00) higher in treatments in the order TR > OR > FP. Tied ridging had a significant effect on actual fodder yield (AFY) in biochar plots, while open ridging significantly affected AFY in no-biochar plots. Annual total mean NFY and AFY increased by 8% and 11% in biochar plots compared to no-biochar plots. In biochar and no-biochar plots, water use efficiency was in the order TR > OR > FP. Conclusively, water use efficiency was significantly higher (p = 0.01) in biochar plots compared to no-biochar plots. Conclusion. When crop production is threatened by soil erosion and drought, mulched tied-ridge with biochar is beneficial to crop growth in rain-fed agriculture, according to this research. Smallholder farmers should be trained on applying this technique for water-saving to mitigate runoff, soil erosion, sediment losses, and improve food security in semiarid areas. [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]

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]