Dalias Panagiotis, Neocleous Damianos
Department of Natural Resources and Environment, Agricultural Research Institute, Nicosia 1516, Cyprus.
Plants (Basel). 2017 Dec 6;6(4):61. doi: 10.3390/plants6040061.
The nitrogen (N) effect of legumes is one of the main reasons for their inclusion in rotation systems and their success in rainfed agriculture of Mediterranean areas. The comparative analysis of this effect in relation to alternative systems or practices is essential for a comprehensive appreciation in their merit. This field experiment was comprised of four three-year rotation cycles. Wheat () was seeded for two consecutive years after common vetch ( L.), treated in three different ways, and after fallow and compared with three wheat monocultures: the conventional one, the continuous straw incorporation, and the sewage sludge incorporation once every three years. Wheat grain and straw yields and N uptake were compared among treatments. Results showed that rotation systems that included vetch were the most promising for improving sustainability. Maximum N uptake and the greatest yield surpluses were obtained when wheat followed vetch incorporated during flowering. When vetch in the rotation was cut for hay or left to fill grains subsequent wheat showed also enhanced yields. Fallow affected the rotation system's fertility due to the incorporation of volunteer plants into the soil. Sewage sludge sustained production without the need for inorganic fertilization during three years. Straw incorporation always gave the smallest yields and N harvests, presumably due to soil N immobilization.
豆科植物的氮素效应是它们被纳入轮作系统以及在地中海地区雨养农业中取得成功的主要原因之一。将这种效应与替代系统或做法进行比较分析，对于全面评估它们的优点至关重要。该田间试验包括四个为期三年的轮作周期。在普通巢菜（Vicia sativa L.）以三种不同方式处理后，连续两年播种小麦（Triticum aestivum），并与三种小麦单作进行比较：传统单作、连续秸秆还田以及每三年一次的污泥施入。比较了各处理间小麦籽粒和秸秆产量以及氮素吸收情况。结果表明，包含巢菜的轮作系统在提高可持续性方面最具潜力。当小麦种植在开花期施入巢菜之后时，氮素吸收量最大且产量盈余也最大。当轮作中的巢菜被割作干草或任其结籽时，随后种植的小麦产量也会提高。由于自生植物混入土壤，休耕影响了轮作系统的肥力。污泥施入能维持三年产量且无需施用无机肥料。秸秆还田的产量和氮素收获量总是最小，这可能是由于土壤氮素固定所致。
