长期肥料试验中玉米籽粒产量趋势Ｐ．Ｃ．Ｎｅｌ等长期试验是获得农业系统长期可持续性信息的重要方法。Ｒｏｔｈａｍｓｔｅｄ的标准点（Ｊｅｎｋｉｎｓｏｎ，１９９１）和依利诺斯大学的Ｍｏｒ－ｒｏｗ小区均为典型的例子。本文描述的田间试验是１９３９年建立的南非最老... Corn Yield Trend in Long-term Fertilizer Experiment. C. Long-term trials such as Nel are important ways to obtain long-term, sustainable information on agricultural systems. The Rothamsted Standard Point (Jenkinson, 1991) and the Mor-row Cell at Illinois University are typical examples. The field experiment described in this article was the oldest in South Africa established in 1939 ...