秸杆直接还田作用有() ["补充和更新土壤有机质,增强微生物的活性","增加土壤养分","改善土壤物理性状","减少水分流失,减轻杂草危害"]
沤肥积制条件有() ["保证嫌气分解条件","适当调节沤肥材料的碳氮比和酸碱度","接种微生物","坑内肥料应适时翻动","加强管理,防止养分损失"]
斜井串车提升时()加装保险绳。 ["必须","不一定","严禁"]
水分是影响微生物活动和堆肥腐熟快慢的重要因素,水分含量一般以占堆制材料最大持水量的()时为宜 ["10%--25%","25%--60%","60%--75%","〉75%"]
要获得优质堆肥,必须满足微生物活动所需要的()条件 ["水分","空气","温度","碳氮比","酸碱度"]
小流域界定面积是多少?