Comparison of Long-Term Organic and Conventional Crop–Livestock Systems on a Previously Nutrient-Depleted Soil in Sweden
Comparison of Long-Term Organic and Conventional Crop–Livestock Systems on a Previously Nutrient-Depleted Soil in Sweden
复制标题
瑞典先前营养耗尽的土壤上长期有机和传统作物-牲畜系统的比较
DOI：
10.2134/agronj2006.0061
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发表时间：
2007
期刊：
影响因子：
2.1
通讯作者：
S. Gesslein
中科院分区：
文献类型：
--
作者：
H. Kirchmann;L. Bergström;T. Kätterer;L. Mattsson;S. Gesslein
一项为期18年的实地研究进行了比较有机和传统种植的高度P和K枯竭的土壤在瑞典南部，没有收到任何无机肥料（或农药）自20世纪40年代中期。系统之间的主要管理差异是：（i）每隔一年的豆类生长和使用豆类作为覆盖作物的有机轮作;（ii）在有机系统中的P的应用率高于常规系统;（iii）排除油菜（甘蓝型油菜L.）有机体系中不含马铃薯（Solanum tuberosum L.）(iv)在有机系统中经常进行机械除草;以及（v）在有机系统中使用固体肥料，在常规系统中使用液体肥料。在有机系统中施用大量的碱性矿渣和磷灰石后，土壤交换性磷的浓度比在常规系统中施用磷肥后增加更多。有机系统，主要依靠豆类为他们的氮供应，将酸化土壤的速度比系统少豆类轮换。有机系统中的作物产量平均比常规系统低50%，杂草生物量比常规系统高（1-3 Mg干物质ha-1）。氮被确定为有机种植作物的主要产量限制营养素。尽管如此，即使使用覆盖作物，有机农业也没有减少氮的淋失。两种系统的土壤碳浓度均有所下降，但有机系统由于较高的碳输入和较低的土壤pH值，土壤碳浓度下降幅度较小。尽管如此，有机农业似乎不是瑞典土壤中碳的一种选择。在将两个系统调整到相同的边界条件以进行无偏建模比较之后，常规系统中的C输入比有机系统高=60%。有机栽培的氮素农学效率为9 ~ 10 kg/kg，常规栽培的氮素农学效率为16-18 kg/kg。磷素的长期利用率有机系统（7%）低于常规系统（36%）。这些结果表明，在冷温条件下，产量和土壤肥力在常规种植制度中具有上级优势。
An 18-yr field study was performed to compare organic and conventional cropping on a highly P and K depleted soil in southern Sweden that had not received any inorganic fertilizers (or pesticides) since the mid-1940s. The major management differences between the systems were (i) growth of legumes every second year and use of legumes as cover crops in the organic rotation; (ii) application of P in the organic system at higher rates than for the conventional system; (iii) exclusion of oilseed rape (Brassica napus L.) from the organic system but inclusion of potato (Solanum tuberosum L.); (iv) frequent mechanical weeding in the organic system; and (v) use of solid manure in the organic and liquid manure in the conventional system. Concentrations of soil-exchangeable P increased more after application of large amounts of basic slag and apatite in the organic system than after application of P fertilizers in the conventional system. Organic systems, which rely mainly on legumes for their N supply, will acidify soils faster than systems with fewer legumes in rotation. Crop yields were, on average, 50% less and weed biomass was greater (1-3 Mg dry matter ha -1 ) in the organic system than in the conventional system. Nitrogen was identified as the main yield-limiting nutrient for organically grown crops. Despite this, and even with use of cover crops, N leaching was not reduced by organic farming. Soil carbon (C) concentrations decreased in both systems, but less so in the organic system due to higher C inputs and lower soil pH values. Still, organic farming seems not be an option for sequestering C in soil in Sweden. After adjusting the two systems to the same boundary conditions for an unbiased modeling comparison, the C input is =60% higher in the conventional system than the organic system. The agronomic efficiency of N was 9 to 10 kg grain yield kg -1 N in the organic system compared with 16-18 kg grain yield kg -1 in the conventional system. The long-term use efficiency of P was lower in the organic system (7%) than in the conventional system (36%). These results show that yield and soil fertility are superior in conventional cropping systems under cold-temperate conditions.