“四改、三增、一及时”是实现白菜优质高产的关键１９９４年，在自然灾害较重，白菜普遍遭受损失的情况下，栾城县两万多亩大白菜却获得平均亩产１１０４３．３公斤的好收成。总结其高产经验，王要是在技术措施上推行了“四改、三增、一及时”。一、“四改”一改零星散乱... “Four changes, three increases, one in time” is the key to achieving high quality and high yield cabbage In 1994, in the case of heavy natural disasters, cabbage generally suffered losses, Luancheng County, 20,000 mu of Chinese cabbage was average yield 11043. 3 kg good harvest. To summarize its high-yielding experience, Wang Yixing implemented the “four changes, three increases and one timely” technical measures. First, the “four changes” changed sporadic scattered ...