煤炭腐植酸作为土壤改良剂对土壤物理性质和小麦产量的影响

在巴基斯坦旁遮普的波特瓦地区(33°N,74°E),集约化土壤耕作,土壤侵蚀和低量作物残体的投入是导致土壤结构退化的原因。结构不稳定的土壤很容易受到侵蚀,反过来,土壤侵蚀又会造成作物产量的下降。因此,为了改善土壤的物理性状,在巴基斯坦旁遮普的干旱地区进行了田间试验。试验地点位于大学(拉瓦尔品第PMAS干旱农业大学)研究农场的园区内。2种不同等级(实验室级和商品级)的腐植酸(HA)各分8个水平,施用2年,处理分别为HL_0(对照,不施腐植酸),HL_1 10 kg HA/hm~2,HL_2 20 kg HA/hm~2,HL_3 30 kg HA/hm~2,HL_4 60 kg HA/hm~2,HL_5 90 kg HA/hm~2,HL_6 120 kg HA/hm~2和HL_7 150 kg HA/hm~2,各处理同时配合施用N-P-K(120-90-60 kg/hm~2)。试验期间,检测土壤总有机碳、饱和导水率、团聚体稳定性、容重、土壤含水量和作物产量。试验结果表明,腐植酸能通过影响土壤总有机碳、饱和导水率、团聚体稳定性、容重和土壤含水量等指标来改善土壤的物理性状。2年试验结果均表现为,实验室级的腐植酸比商品级的腐植酸能更好地改善土壤物理性状,从而提高小麦产量。2种不同级别的腐植酸各施用水平与对照相比,差异均显著。在120 kg/hm~2和150 kg/hm~2的腐植酸施用水平下,大多数指标均显示出了相似的结果,因此,从经济角度考虑,120 k g/hm~2的腐植酸用量为最佳施用量。

Use of Coal Derived Humic Acid as Soil Conditioner to Improve Soil Physical Properties and Wheat Yield

In Pothwar area of Punjab Pakistan (33o N to 74o E), intensive soil tillage, soil erosion and low crop residue input are the reasons which have lead to the deterioration of soil structure. Structurally unstable soils are more susceptible to erosion which, in turn, leads to poor crop productivity. Therefore, a ifeld study was conducted in dry land region of Punjab, Pakistan to improve soil physical health at campus of University Research Farm (PMAS Arid Agriculture University, Rawalpindi). Two different grades (Laboratory and commercial grade) of humic acid along with eight levels were applied for two years. The treatments were HL0 (control), HL1 10 kg HA/hm2, HL2 20 kg HA/hm2,HL3 30 kg HA/hm2, HL4 60 kg HA/hm2, HL5 90 kg HA/hm2, HL6 120 kg HA/hm2, and HL7 150 kg HA/hm2 with a basal recommended dose of N-P-K (120-90-60 kg/hm2). Soil parameters such as total organic carbon, saturated hydraulic conductivity, aggregate stability, bulk density, soil water contents and grain yield were recorded. Results showed that humic acid improved the soil physical health in terms of total organic carbon, aggregate stability, saturated hydraulic conductivity, bulk density and soil water contents. Laboratory grade humic acid improved physical properties more as compared to commercial grade humic acid for the wheat production by improving soil health during both the years. Differences among applied levels of both grades of humic acid were statistically signiifcant than control. Most of the parameters showed similar results at 120 and 150 kg/hm2 applied levels of humic acid, so 120 kg/hm2 dose rate is an economical level of humic acid than 150 kg/hm2 level.