生物炭施入3年后对热带地区玉米生长发育和产量的影响

为明确生物炭在热带地区玉米（Zea mays）上的应用效果，设置施用花生壳、水稻壳2种生物炭类型（施用量为10、20、40、60 t·hm−2），以不施生物炭为对照（CK），探究在生物炭施入3年后对玉米的生长发育、养分积累、产量及土壤特性的影响。结果表明：整个生育期中，玉米的株高及叶片SPAD值在各处理间都没有显著差异；而在吐丝期，40 t·hm−2处理的玉米叶片SPAD值显著高于60 t·hm−2处理。另外，随着生物炭施用量的增加，在玉米成熟期0～40 cm土层的土壤pH值、有机碳、铵态氮、速效磷、速效钾含量都逐渐增加；除40 t·hm−2处理外，60 t·hm−2处理较其他处理能显著提高土壤pH、有机碳、铵态氮、速效磷、速效钾含量，同时，40 t·hm−2处理下土壤铵态氮和速效磷与CK间无显著差异。40 t·hm−2处理的玉米干物质积累量、氮磷钾积累量、穗粒数和产量达到最高，显著高于CK处理；但其氮、磷、钾利用效率与CK间无显著性差异。相关分析发现，产量与土壤pH值、干物质积累量、植物氮、磷、钾积累量和穗粒数都呈显著正相关。综合来看，40 t·hm−2生物炭施用水平能改善土壤、提高玉米的生长和养分利用及产量，可作为热带地区最佳施用量，且水稻壳生物炭要优于花生壳生物炭。

English. In order to clarify the effect of biochar application on maize (Zea mays) in the tropics, two types of biochar, peanut hull biochar and rice hull biochar, were applied to the maize field at the rates of 10, 20, 40, and 60 t·hm−2), with no biochar as the control (CK), to observe their effects on the growth, development, nutrient accumulation and yield of the maize, and the soil properties in the maize field three years after biochar application. The results showed that the plant height and leaf SPAD values of maize were not significantly different among treatments throughout the reproductive period, while at the silking stage, the leaf SPAD values of maize in the 40 t·hm−2 treatment were significantly higher than those in the 60 t·hm−2 treatment. In addition, with the increase of biochar application rate, the soil pH and the contents of organic carbon, ammonium nitrogen, soil available phosphorus and soil available potassium in the 0～40 cm soil layer at the maturity stage of maize increased gradually. Except for the 40 t·hm−2 treatment, the 60 t·hm−2 treatment significantly increased the soil pH, and the contents of organic carbon, ammonium nitrogen, soil available phosphorus and soil available potassium as against the other treatments. At the same time, there was no significant difference in the contents of soil ammonium nitrogen and soil available phosphorus between the 40 t·hm−2 treatment and CK. The 40 t·hm−2 treatment had the highest accumulation in maize dry matter, nitrogen, phosphorus and potassium, and was highest in number of grains in ears and yield, which were significantly higher than those of the CK treatment. However, there was no significant difference in utilization efficiency of nitrogen, phosphorus and potassium between the 40 t·hm−2 treatment and CK. Correlation analysis found that yield was significantly positively correlated with soil pH, dry matter accumulation, plant N, P and K accumulation and number of grains in ears. Taken together, the 40 t·hm−2 biochar treatment could improve the soil and the growth and nutrient utilization and yield of maize, which could be optimal in the tropics, and rice hull biochar was superior to peanut hull biochar.