Mak-Mensah Erastus, Sam Faisal Eudes, Safnat Kaito Itoba Ongagna Ipaka, Zhao Wucheng, Zhang Dengkui, Zhou Xujiao, Wang Xiaoyun, Zhao Xiaole, Wang Qi
College of Grassland Science, Gansu Agricultural University, Lanzhou, Gansu Province, China.
College of Food Science and Engineering, Gansu Agricultural University, Gansu Key Laboratory of Viticulture and Enology, Lanzhou, Gansu Province, China.
PeerJ. 2021 Aug 25;9:e11889. doi: 10.7717/peerj.11889. eCollection 2021.
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.
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).
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.
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.
在雨养农业中，土壤侵蚀导致有机物质和矿物质养分流失是一个全球性的严重问题，在中国黄土高原地区尤为突出。因此，通过生物炭垄沟集雨提高雨水利用效率有望提高农业生产力。然而，由于对生物炭垄沟集雨的了解有限，小规模农户面临采用该技术的挑战，这也是本研究的原因所在。
进行了一项田间试验，以确定在苜蓿生长年份（2020年），以无垄沟的平作（FP）为对照，研究垄上使用可降解薄膜和沟中使用生物炭的敞垄（OR）和绑垄（TR）方式对坡地径流、泥沙流失、土壤水分、饲料产量和水分利用效率（WUE）的影响。
生物炭使平作（30%）、敞垄（45%）和绑垄（52%）的径流减少，同时平作（33%）、敞垄（43%）和绑垄（44%）的泥沙也减少。与无生物炭地块相比，生物炭地块的平作（31%）、敞垄（45%）和绑垄（50%）的平均径流效率较低。在苜蓿生长季节，生物炭和无生物炭地块中，绑垄垄上的土壤温度高于敞垄，敞垄高于平作。苜蓿生长季节生物炭和无生物炭地块沟中的土壤温度顺序为平作>敞垄>绑垄。生物炭地块中平作、敞垄和绑垄的平均土壤储水量高于无生物炭地块。这表明生物炭对敞垄有有益影响。年总净饲料产量（NFY）显著（p = 0.00）高于处理组，顺序为绑垄>敞垄>平作。绑垄对生物炭地块的实际饲料产量（AFY）有显著影响，而敞垄对无生物炭地块的AFY有显著影响。与无生物炭地块相比，生物炭地块中年总平均NFY和AFY分别增加了8%和11%。在生物炭和无生物炭地块中，水分利用效率顺序为绑垄>敞垄>平作。总之，与无生物炭地块相比，生物炭地块的水分利用效率显著更高（p = 0.01）。
根据本研究，当作物生产受到土壤侵蚀和干旱威胁时，生物炭覆盖绑垄对雨养农业中的作物生长有益。应培训小农户应用这项节水技术，以减少径流、土壤侵蚀和泥沙流失，提高半干旱地区的粮食安全。
