大豆秸秆基保水剂对南阳烟田土壤物理性状及烟叶生长的影响

Effects of soybean straw-based water retaining agent on tobacco growth and soil physical properties of tobacco field in Nanyang

为了促进大豆秸秆基保水剂在农业生产中的应用和推广,作者在河南南阳旱区利用田间试验考察了保水剂用量对烟田土壤物理性状和烟叶生长的影响。结果表明,烟田施用大豆秸秆基保水剂可以显著抑制土壤水分的流失,并且抑制作用随保水剂用量的增加而增强;同时保水剂改善了土壤物理性状,降低土壤体积质量,使土壤孔隙数量增加,提高了土壤总孔隙度,尤其增加了非毛管孔隙度,增强了土壤通气性能。但施用过量容易降低土壤非毛管孔隙度,造成土壤板结;保水剂还可以降低烟叶的蒸腾速率,改善其光合特性,提高水分利用效率,增强烟叶抗旱性,从而提高烟叶株高、茎围和最大叶面积等农艺性状,改善烟叶化学成分。保水剂用量为240 kg/hm2时,土壤平均含水率较对照提高3.1%,总孔隙度提高6.8%,烟叶增产18.4%,上等烟比例提高6.8%。

In order to promote the application and promotion of soybean straw-based water retaining agent（WRA） in agriculture,effects of WRA rate on soil physical prorerties and tobacco growth were studied by the field experiment in dry area of Nanyang,Henan province.The results showed that water loss was reduced by WRA obviously with its application amount,and the WRA improved soil physical properties,increased the porosity in soil and decreased soil bulk density.WRA application enhanced the total soil porosity,especially non-capillary porosity,and consequently improved the soil aeration condition.However,excessive application of WRA reduced non-capillary porosity,leading to soil compaction.Furthermore,the application of WRA decreased transpiration rate of tobacco,improved leaf photosynthetic characteristics and water use efficiency,and strengthened drought resistance of tobacco.It also enhanced the plant height,stem thickness and maximum leaf area of tobacco,and improved the tobacco quality.The average moisture content of soil,total soil porosity,yield and the proportion of superior tobacco increased by 3.1%,6.8%,18.4% and 6.8% respectively when the suitable application rate of WRA was 240 kg/hm2.