东北农牧交错带玉米田收获高品质粗饲料方法研究Ⅰ--玉米去雄摘叶对产量及秸秆饲用价值的影响

Study on harvesting high quality roughage in corn field of the ecotone between agriculture and animal husbandry in Northeast China——Effects of detasseling and defoliating on yield and corn straw feeding value

在东北农牧交错带玉米田中两种垄距种植玉米，吐丝期对玉米进行三种去雄摘叶（去雄穗＋1顶叶。去雄穗＋2顶叶，去雄穗＋3顶叶）处理，收获膏绿秸秆作饲料。研究不同去雄摘叶处理对产量及鲜秸秆饲用价值的影响。结果表明：窄垄种植玉米三种去雄摘叶的处理与不去雄摘叶传统垄距种植的玉米产量比较，增产16．6％～32％，又可获得较多的含粗蛋白高、消化率大的青绿秸秆，并提供较多的代谢能。如果仍然保持传统垄距种植，去掉雄穗＋1个顶叶的处理产量略高于不去雄摘叶的对照并可获取优质青绿秸秆。因此，在不影响玉米籽实产量的前提下，提前收获青绿秸秆，将为东北农牧交错带家畜提供营养价值高，适口性好可替代部分饲草的青绿饲料，为发展草地农业，缓解草原压力提供可行途径。

To study the effect of different detasseling and defoliating treatments on yield and straw feeding value, the corn was planted in two row space in corn field of the ecotone between agriculture and animal husbandry in Northeast China and detasselled and deleaved for three treatments at silking stage, then the green corn straw were cut for feeding livestock. The result showed that three treatments of detasseling and defoliating 1 - 3 top leaves for corn with narrow row space can increase yield by 16.6% - 32% in comparison with no detasseling and defoliating treatment with conventional row space, it can also produce more green corn straw with high content of crude protein and digestibility, and more metabolizable energy. The yield of detasseling and defoliating 1 tip leaf treatment was higher than that of contrast treatment and obtain corn straw with high content of crude protein and digestibility when planting corn with the conventional row space. So cutting the green corn straw earlier in the condition of no effect on yield can supply green corn straw with higher nutritional value and better palatability for livestock which can substitute to forage grass in the ecotone between agriculture and animal husbandry in Northeast China. These are doable approaches for developing the grassland agriculture and lessen the grassland pressure.