中型拖拉机压实对测试截面土壤坚实度和含水率的影响

Effects of medium tractor compaction on soil penetration resistance and moisture content of testing cross section

以黑龙江省黑土区垄作旱田为研究对象,采用中型拖拉机开展压实试验,提出一种农业机械压实后土壤坚实度和含水率试验数据测试创新方法,对科学合理使用农业机械、保持和提升黑土区耕地生产能力具有重要理论和实际意义。设压实1~5次及对照(CK)6种处理,测试时,在压实辙印垂直方向以辙印中点为中心取7个测点(每测点间隔10 cm),测量0~40 cm土层土壤坚实度和0~20 cm土层土壤含水率。结果表明,中型拖拉机压实对压实辙印下方及两侧土壤均产生影响,拖拉机压实后测试截面明显形成土壤坚实度较大影响区域,其影响范围和程度随压实次数增加而增加;在0~20 cm土层,连续压实2~5次后测试截面土壤坚实度超过1000 kPa,影响作物根系生长发育;中型拖拉机压实对辙印下方5~20 cm土层土壤坚实度影响最大,压实5次处理土壤坚实度与对照相比增加107.4%,且各压实处理土壤坚实度随测试深度增加均呈类似"鼻形"曲线;土层深度、压实次数、测点位置及各因素交互作用均为影响土壤坚实度显著因素(P<0.01),其中土层深度和压实次数为最重要因素;中型拖拉机压实致使辙印下方0~20 cm土层土壤含水率增高,与两侧测点相比增加11.3%~27.6%,与对照相比增加25.8%~36.7%。

Took typical upland black soil area in Heilongjiang province as the research object,adopt medium tractor implement compaction test,this article proposed an innovative method for testing soil penetration resistance and moisture content after agricultural machinery compaction.Study the influence of agricultural machinery compaction on the soil physical properties had important theoretical and practical significance for the scientific use of agricultural machinery,maintaining and improving the productivity of cultivated land in the black soil area.A total of six treatments for compaction 1-5 times and uncompacted contrast(CK),took seven measuring points in the vertical direction of the compacted rut with the midpoint of the rut as the center(each measuring point interval of 10 cm),measured soil penetration resistance of 0-40 cm soil layer and soil moisture content of 0-20 cm soil layer.The research results showed that,with the increase of compaction times by the medium-sized tractor,the soil penetration resistance of the testing cross section increased,and the soil penetration resistance under the compaction trace increased most obviously;At the 5-20 cm soil layer and the testing points of10-50 cm,after compaction the test cross section obviously formed a compaction affected area with larger soil penetration resistance,and its impact range and extent increased with the increase of compaction times;In the soil layer of 0-20 cm,the soil penetration resistance of the contrast treatment was less than 800 kPa,but after continuous compaction for 2-5 times,the soil penetration resistance exceeded 1000 k Pa,which affect the growth and development of crop roots;Below the rut,the area of with larger soil penetration resistance increased with the increase of compaction times,and the area with little soil penetration resistance decreased with the increase of compaction times.The soil penetration resistance of the 0-20 cm soil layer changed the most and the soil penetration resistance of each compaction treatment showed a"nose-shaped"curve as the testing depth increased,and with the increase of the compaction times,the nose-shaped area became more and more obvious;Soil layer,compaction times,testing points and the interaction of various factors were all significant factors affecting soil penetration resistance(P<0.01),of which the soil layer and compaction times were the most important factors;The medium-sized tractor compaction,resulting in an increase in the soil moisture content of the 0-20 cm soil layer below the rut,which increased by 11.3%-27.6%compared with the testing points on both sides.Compared with the contrast treatment,the soil moisture content of each compaction treatment increased by 25.8%-36.7%.