施用生物炭对华北平原土壤水分和夏玉米生长发育的影响

2014～2017年在中国农业大学吴桥实验站设每年施用生物炭7 200 kg/hm~2(T1)、3 600 kg/hm~2(T2)、1 800 kg/hm~2(T3)和不施生物炭(CK)4个处理,探究施用生物炭对土壤水分和夏玉米生长发育的影响。结果表明,与CK处理相比,T1和T2处理的子粒产量分别降低10.59%～10.80%和6.30%～7.76%(P0.05)。施用生物炭显著降低全生育期的耗水量,提高水分利用效率。与T3和CK处理相比,T1和T2处理显著降低主要生育时期的SPAD值、光合速率、气孔导度和蒸腾速率,花后的叶面积指数也较低,从而降低花后的干物质积累。施用生物炭可以增加土壤含水量,减少夏玉米耗水量,进而提高水分利用效率;中高量的施用降低夏玉米和周年的子粒产量。因此,在华北平原生物炭施用量建议以低量为宜。

Effects of Biochar on Soil Water and Growth of Summer Corn in the North China Plain

A field experiment was conducted to study the impact of biochar on soil water and growth of summer corn under a wheat-corn rotation system in the North China Plain. Four treatments, including 7 200 kg/ha(T1), 3 600 kg/ha(T2), 1 800 kg/ha(T3) and 0(CK) biochar applying yearly, were conducted during 2015-2017 at Wuqiao experi-mental station of China Agricultural University, Hebei Province. The results indicated that, compared with the CK, the grain yield of T1 and T2 decreased by 10.59%-10.80% and 6.30%-7.76% respectively(P<0.05). However, bio-char addition significantly reduced the water consumption and improved water use efficiency of the whole growth pe-riod by 13.72%-24.43%(P<0.05). Compared with the T3 and CK, T1 and T2 significantly decreased SPAD value, photosynthetic rates, stomatal conductance, and transpiration rates of corn main growing stages, leaf area index and dry matter accumulation after flowering. In summary, biochar addition could increase soil water content, reduce the water consumption, and improve water use efficiency. However, the grain yield of summer corn and whole year is de-creased under the middle and high biochar addition rates. Therefore, the amount of biochar is recommended to be low in the North China plain.