红壤调理剂的改土培肥及作物增产研究

在南方红壤地区,土壤酸化加剧、养分贫瘠化严重,研发红壤改良的技术和物化产品,对作物均衡增产和红壤可持续利用有重要意义。红壤旱地连续3年定位种植油菜-花生,花生品种为赣花5号,油菜品种为丰油730。调理剂为自行研制的专利产品,已经实现了产业化。研究了红壤调理剂对土壤微结构、物理性状、养分和pH值的影响,并对花生、油菜的产量进行了分析。结果表明:1)施用调理剂后,从微观结构来看,红壤的致密性降低、孔隙度增加,土壤颗粒直径4μm;2)施用调理剂的土壤容重显著降低,孔隙度增加到59%以上,大颗粒水稳性团聚体(0.25 mm)含量增加幅度为1.6%~14.0%,分形维数显著降低,并且与0.25mm粒径的团粒结构含量间呈极显著线性相关;3)施用调理剂的土壤电导率、有机碳、矿质态氮、有效磷、速效钾含量均提高,提高幅度在4.3%~143.7%之间;4)施用调理剂还降低了红壤的酸性,pH值从对照处理的5.28提高到5.82,差异显著;5)施用调理剂,花生和油菜增产幅度分别在13.1%~24.8%、10.3%~21.6%之间;6)应用笔者研制的红壤调理剂,可有效改善红壤旱地的理化性质,提高油菜和花生产量,其用量在2 250~3 000 kg/hm~2时较佳。

Effect of botanical soil conditioners on the soil fertility and crop yield in the red soil

In the red soil region of southern China, the soil acidification is increasingly sharpening and the soil nutrients is get-ting more impoverished, so the study on the techniques of red soil improvement and corresponding materialized products is very important for yield increasing and the red soil sustainable utilization. Through three years continuous experiment of peanut-rape rotation cropping in dry land red soil, the effect of botanical soil conditioners on the red soil microstructure, physic characteris-tics, nutrient and pH value were researched, moreover, its effects on the yield of peanut and rapeseed were analyzed. The re-sults indicated: 1) As for the microstructure, the compaction of red soil declined, the diameter of the soil particle<4 μm, but the porosity increased after soil conditioners application. 2) The bulk density of soil significantly decreased after soil condi-tioners application, the porosity increased to over 59%, the increased range of big granule water stable aggregate content ( >0. 25 mm) was 1. 6% ~14. 0%, fractal dimension significantly reduced, and it was significantly and linearly correlated to the content of aggregate structure whose particle diameter was more than 0. 25 mm. 3) The soil conductivity, the content of organ-ic carbon, mineral nitrogen, available phosphorus and potassium were improved by a range of 4. 3% ~143. 7% after soil con-ditioners application. 4) The red soil acidity was significantly reduced under soil conditioners application. Soil pH value in-creased from 5. 28 (CK) to 5. 82. 5) Soil conditioners application increased the yields of peanut and rapeseed by 13. 1% ~24. 8% and 10. 3% ~21. 6% respectively. 6) Based on the above results, it was concluded that the tested soil conditioner could effectively improve the red soil physical and chemical properties and subsequently improve the crops yield, and the opti-mal application rate was about 2250~3000 kg/hm2 on the red soil.