陕北榆林和延安两专区境内大部是黄土丘陵沟壑,耕地多位于陡坡上。由于过去在耕作制度上习惯于广种薄收,使天然植被受到严重的破坏,加以黄土结构松散易受侵蚀,每当夏季暴雨来临期间,水土流失现象非常严重,以致坡地越耕越陡,土层越种越薄,农作物产量长期陷于低落水平,丰年亩产不过百斤,(?)年仅三、五十斤。党和政府早就针对当地自然特点,抓紧了水土保持工作,提出坡沟兼治的正确方针,并已取得了很大成就。然而工作的进展不够平衡,特别是农业技术和农业改良土壤措施方面不能满足迅速提高产量的要求。例如几年来推行的套(?)沟播、垅作区田、平播培垅、串 Yulin, Shaanxi and Yan’an two areas within the territory of most loess hilly gully, mostly in steep slopes. Due to the past tillage system accustomed to a wide range of thin income, so that the natural vegetation was severely damaged, loess structure loosening vulnerable to erosion, each summer heavy rains, soil erosion is very serious, so that the sloping land more plowing, the more the soil layer The thinner, crop yields have long been at a low level, but harvest pounds, (?) Only three or five pounds. The party and government have long targeted the local natural features, stepped up soil and water conservation work, put forward the correct guideline for governing both the broad and the deep and achieved great successes. However, the progress of work is not balanced enough. In particular, agricultural technologies and agricultural improvement of soil measures can not meet the requirement of rapidly increasing output. For example, a few years ago the implementation of the sleeve (?) Sowing, Zuo Zuotian, flat broadcast training, string