土壤的紧密度,对作物生育、产量的影响,在农业科学通讯1955年第4期,已有初步介绍。我们为了进一步找出生产上更可靠的数据,今年在通县拖拉机站代耕代播地,进行了调查研究,结果证明,播前镇压,都得到了良好的效果。四个生产合作社,有两个进行了播前镇压,两个因雨后抢种,未及镇压,小麦生长不如镇压过的。但拖拉机轮压过的地方,因为起了播种前镇压的作用,从返青开始,就看出生长比较好,苗较高而整齐,在产量上,我们作了单打单 Soil compactness, the impact on crop growth, yield, in Agricultural Science Newsletter 1955, No. 4, has been initially introduced. In order to find out more reliable data on production, we conducted a survey and study on behalf of the sowing and planting sites at the tractor station in Tong County this year. The results show that the pre-sowing crackdown has achieved good results. Two of the four production cooperatives carried out pre-broadcast repression, two were prematurely razed and razed, and the suppression of wheat was not as good as the growth of wheat. But the tractor wheeled place, because of the role played before the suppression of sowing, starting from the green, we can see that growth is relatively good, high and neat seedlings, in terms of production, we made a singles list