Verification of traffic-induced soil compaction after long-term ploughing and 10 years minimum tillage on clay loam soil in South-East Norway

Grain yields are presented from a 10-year field trial with four tillage regimes (annual ploughing, harrowing only, ploughing/harrowing alternate years and minimum tillage) on clay loam. We also present soil physical analyses and use the compaction verification tool (CVT) to assess compaction on plots with annual ploughing and minimum tillage, after using slurry tankers with contrasting wheel loads (4.1 Mg, 6.6 Mg) and wheeling intensities (1×/10×) in the 11th trial year, and yields monitored two years after compaction. Winter wheat yields in the period before compaction were strongly affected by tillage, with annual ploughing giving on average 24% higher yield than direct drilling. Both wheat and oats were far less affected in treatments with harrowing only or ploughing/harrowing alternate years, on average within 6% of annual ploughing. Yields after compaction were affected by both previous tillage and compaction intensity. In the first year, single wheeling after annual ploughing gave 23% yield reduction with 4.1 Mg wheel load and 28% reduction with 6.6 Mg wheel load, whilst multiple wheeling gave 14% reduction at 6.6 Mg wheel load. Yield reductions after minimum tillage ranged from 63% (single wheeling with 4.1 Mg) to 100% (multiple wheeling with 6.6 Mg). Similar trends were found in the second year. The soil physical data indicated that all wheeling led to changes in bulk density, pore sizes and permeability in both topsoil and subsoil on both sampled tillage plots. However, effects in the subsoil were partly masked by the soil's high initial bulk density, partly due to its high clay content. The CVT, which plots air capacity against hydraulic conductivity, suggested some harmful compaction on both plots, with the minimum tillage plot being less affected than the ploughed plot. However, yield results did not support this conclusion, indicating that other factors limited yields on the minimum tilled plot.     

Single and combined application of two-phase olive mill waste and dairy cattle slurry to soil: Short-term effects on N and C dynamics

Abstract

Two-phase olive mill waste (TPOMW) and dairy cattle slurry (CS) are two organic materials with low economic value and limited potential for reutilization despite their high concentrations of nitrogen (N) and organic matter. A laboratory incubation for ca. 100 d was performed to assess the short-term N and carbon (C) dynamics in a soil amended with TPOMW, CS and a mixture of both materials in order to: (i) explore the potential benefits of mixing TPOMW with CS to promote mineral N immobilization and avoid nitrate leaching, and (ii) assess the potential for increased soil C stocks after TPOMW, CS or TPOMW+CS application. Our results clearly showed that the combined application of TPOMW+CS caused N immobilization; hence, it contributes to tying up the applied N, resulting in a decrease of critical N leaching, which is usually observed after CS application. No clear N mineralization was observed in the TPOMW+CS treatment during the incubation period.

It appears that an application of 30 Mg ha^?1 of TPOMW is enough to decrease net N mineralization from applied CS, as the C:N ratio of the mixture TPOMW+CS is 27. More than 40% of the TPOMW-derived C remained in the soil at the end of the experiment in treatments with single and combined application of TPOMW+CS, indicating that such materials have the potential to increase C stocks in soil. It can be concluded that a combined application of TPOMW+CS is of interest to maintain the CS-derived N in organic form during a longer time period and minimize risks of nitrate leaching, although further studies are necessary to define a better TPOMW:CS ratio which allows a proper plant N uptake.     

The effect of applying cattle slurry using the trailing‐shoe technique on dairy cow and sward performance in a rotational grazing system

The effects of applying cattle slurry using the trailing‐shoe technique on dairy cow and sward performance were examined in two experiments in Northern Ireland. In Experiment 1, forty‐eight cows were allocated to two treatments, with or without slurry application. In Experiment 2, sixty cows were allocated to four treatments, a combination of high and normal grazing stocking rate, with or without slurry application. In Experiment 1, slurry was applied during the first and fourth rotations. In Experiment 2, slurry was applied prior to the first grazing rotation and during the second, fifth and sixth grazing rotations. In Experiments 1 and 2, the total inorganic fertilizer nitrogen (N) inputs applied within the slurry treatments were 200 and 133 kg N ha^?1, with 280 and 285 kg N ha^?1 used within the fertilizer‐only treatments in each experiment respectively. Varying responses of milk yield to slurry application were observed. In Experiment 1, with a normal stocking rate, no effect was observed. In Experiment 2 with two stocking rates, reduced milk yields were observed at both stocking rates. Although not significant, there were indications that this reduction in milk yield when slurry was applied was higher at higher stocking rates.     

沼液在水稻秧苗培育中的应用

研究了不同浓度沼液对杂交水稻种子浸种和秧苗培育的影响,结果表明,使用沼液比重在1.002-1.005 g/cm3,对杂交稻种子发芽率、成秧率和秧苗生长质量都有良好的促进作用,同清水对照相比,其发芽率、成秧率和秧苗生长质量各项指标都达到显著或极显著,但使用超过比重为1.009 g/cm3时都有明显的抑制作用,发芽率降低,秧苗生长不均匀。     

熊猫粪和竹子叶厌氧发酵产沼气效果比较

[目的]比较熊猫粪和竹子叶厌氧发酵产沼气效果。[方法]分别以熊猫粪和竹子叶为原料,在30℃下进行批量式恒温沼气发酵试验,比较熊猫粪和竹子叶厌氧发酵产沼气效果。[结果]熊猫粪沼气发酵时间为40 d,原料产气率为50 ml/g,TS产气率为121 ml/gTS,VS产气率为123 ml/g VS;竹子叶发酵时间为92 d,原料产气率为83 ml/g,TS产气率为168 ml/g TS,VS产气率为197 ml/g VS。[结论]两种原料均可作为沼气发酵原料,竹子叶的产气潜力和降解效果明显好于熊猫粪,但熊猫粪的发酵时间仅为竹子叶发酵时间的2/5,表明经过大熊猫消化后的熊猫粪更易于发酵。     

地源热泵式中、高温厌氧发酵加温系统比选分析

[目的]筛选沼气工程发酵系统。[方法]比较70 m3/d日产气量的中型沼气工程用的地源热泵式中温厌氧发酵加温系统(池容产气率1 m3/(m3.d))和地源热泵式高温厌氧发酵加温系统(池容产气率2.2 m3/(m3.d))2种加温方案,计算其沼气池理论加温负荷、系统初投资以及运行费用,并分析了2者的技术可行性和经济效益。[结果]高温厌氧发酵系统的初投资比中温厌氧发酵系统少8.3万元,年运行费用少2 711元,投资效益净现值为123 333元。[结论]分析表明在加温系统的生命周期内,高温厌氧发酵系统具有更好的投资效益。     

酒糟与猪粪混合厌氧发酵产沼气的研究

为探索酒糟中添加猪粪对厌氧消化特性的影响,采用自行设计的小型厌氧发酵装置进行批量发酵试验。结果表明,酒糟与猪粪的干物质质量比为7∶3时,发酵过程中日均产气量、累积产气量、甲烷体积分数都最大;pH的降低幅度最小,抑制酸化效果最佳;总产气量和总固体产气量分别为31 885 mL、263.9 mL/g,与其他各组有显著差异。因此,合理调配酒糟与猪粪的比例,能够有效调节料液碳氮比,从而提高酒糟的产气率与利用率。     

沼液对莱阳梨生长发育和品质的影响

探讨了沼液追施对莱阳梨生长发育及品质的影响,结果表明:追施沼液可以增加梨树营养,促进生长发育和花芽分化,增强了光和作用能力。果树长势健壮,抗病力增强,成花率、坐果率明显提高。梨生长迅速,增重快,果重提高39.3%,品质明显改善,含糖量提高12.7%,且光泽度好,成熟度一致。     

京郊大中型沼气工程沼液养分及重金属含量分析

为指导沼液的高效合理施用,对4种不同发酵原料的沼液养分及重金属含量作了分析.结果发现:牛粪(n=7)和混合原料(n=4)厌氧发酵产生的沼液有机质含量比猪粪(n=6)和鸡粪(n=3)原料偏高,不同原料沼液的全氮、全磷、全钾养分含量差异不大,沼液过0.5mm筛后,沼液有机质、全氮、全磷、全钾含量均有所降低.沼液样品中可以检出重金属铬、汞,镉等,但未超过有机肥料中对重金属含量的限量标准.     

稻草与牛粪混合连续厌氧消化制备生物燃气研究

以挥发性固体比1:1的稻草与牛粪为混合原料,采用40 L有机玻璃反应器进行连续厌氧消化,考察不同有机负荷率(OLR)3～12 kg/(m3·d)及温度对厌氧消化性能及稳定性的影响.结果表明,高温消化在整个OLR范围内,池容产气率逐渐增加,最高达到5.26 m3/(m3 ·d),平均挥发性固体产气率在OLR为3.6 kg/(m3 ·d)时达到最大值489.6L/kg;中温消化在OLR为12 kg/(m3·d)时出现严重的VFAs抑制,在无挥发性脂肪酸抑制的OLR范围(3～8 kg/(m3·d))内,池容产气率逐渐增加,最高达到2.57 m3/(m3·d),平均挥发性固体产气率在OLR为3.6 kg/(m3·d)时达到最大值440.0L/kg;当OLR升高到8 kg/(m3 ·d)时,中温和高温发酵系统均出现了严重的污泥膨胀.