不同施用量水稻灰对作物及退化黄壤理化性质的影响

The Effect of Different Application Amounts of Rice Biomass Ash on Crops and Degraded Yellow Soil

以退化黄壤为对象,通过莴笋盆栽试验,研究了不同施用量的水稻灰（0,10,25,50,100,250g/kg）对作物品质及退化黄壤理化性质的影响,并进一步分析了水稻灰不同施用量下土壤液塑限的变化。结果表明：（1）水稻灰的施用提高了莴笋氨基酸和还原糖含量,以施用量为50~100g/kg的处理效果较佳,但仅施用量为50g/kg时的莴笋硝酸盐与处理I（0g/kg）比较减少了54.9%;水稻灰施用能提高莴笋中全氮、全磷、全钾含量,且随着灰渣施用量的增加而逐渐升高,但过量水稻灰处理（250g/kg）的莴笋全氮、全磷含量的增加量较其他灰渣处理明显减少。（2）水稻灰处理提高了退化黄壤pH值,改善了土壤酸化情况,其中处理V（100g/kg）的退化黄壤pH值由4.84上升至7.13。水稻灰施用可有效提高土壤有效磷和速效钾含量,但对碱解氮的作用并不明显。（3）各处理〉0.25mm土壤团聚体水稳定性表现为处理V（100g/kg）〉处理IV（50g/kg）〉处理III（25g/kg）〉处理VI（250g/kg）〉处理II（10g/kg）〉处理I（0g/kg）,其中处理V的〉0.25mm团聚体破坏率由63.1%减至17.6%,同时对〉0.25mm土壤团聚体水稳定性提高效果最佳,但过量施用水稻灰（250g/kg）改良效果降低,〉0.25mm团聚体破坏率达到了42.4%。土壤液、塑限则随水稻灰施用量增加而增加,其中250g/kg水稻灰处理分别为31.67%,46.8%,有效提高了退化黄壤的保水能力。总体上,水稻灰施用量在50~100g/kg时,对退化土壤的养分环境、物理结构及作物养分品质的综合改良效果最佳。

The lettuce pot experiment was designed based on the degraded yellow soil to explore the effect of different application amounts of rice biomass ash（0,10,25,50,100,250g/kg）on the quality of crops and the physical and chemical properties of degraded yellow soil,as well as analyze the change of soil liquid limit and plastic limit with different application amount of biomass ashes,for the purpose of providing practical basis for the improvement of degraded soil and the appropriate application of biomass ashes.The results showed that：（1）Biomass ash improved the contents of amino acids and reducing sugars in lettuce,and the effect of treatment with 50—100g/kg application amount was better,but only with 50g/kg application amount the nitrate content in lettuce reduced by 54.9%,compared with the treatment I（0g/kg）.Besides,biomass ash could promote the contents of total nitrogen,total phosphorus and total potassium in lettuce,which were rising with the increase of application amount of biomass ashes.However,in the treatment of excessive amount biomass ashes（250g/kg）,the contents of total nitrogen and total phosphorus in lettuce obviously increased less than those in other ashes treatments.（2）In the treatment of biomass ashes,the pH of degraded yellow soil increased and the state of soil acidification was improved,while the pH of degraded yellow soil in the treatment V（100g/kg）rose to 7.13 from 4.84.The biomass ashes were beneficial to improving the content of effective phosphorus and rapidly-available potassium,but not clearly useful to alkali-hydrolyzable nitrogen.（3）Water stability of aggregates（〉0.25mm）in soil was described as the order：treatment V（100g/kg）〉IV（50g/kg）〉III（25g/kg）〉VI（250g/kg）〉II（10g/kg）〉I（0g/kg）.Destruction rate of aggregates（〉0.25mm）reduced to 17.6%from 63.1%in treatment V（100g/kg）,and water stability of macro-aggregates（〉0.25mm）in soil was improved obviously.Meanwhile,improvement effect lowered with excessive biomass ashes application（more than 250g/kg）,and destruction rate of aggregates（0.25mm）declined to 42.4%.On the contrary,liquid limit and plastic limit of soil increased along with the addition of biomass ash application amounts,and both of them reached 31.7%and 46.8%in the treatment VI（250g/kg）,effectively improving water retention of degraded yellow soil.On the whole,when the application amount of biomass ash was 50—100g/kg,the best comprehensive improvement effect could appear in the aspects of nutrient environment,physical structure of degraded yellow soil and the nutrient quality of crops.