Organic cultivation system of corn–triticale rotation using white clover living mulch

We conducted an on‐farm experiment to establish corn–triticale rotational cropping system for producing organic forage, using white clover living mulch (LM). A 2‐ha experimental field has been managed according to the Japanese Agricultural Standard for organic feed production since 2003, and two cropping systems (LM and tillage cultivation [TC]) combined with two compost application methods (with and without compost application before planting) were tested as four corn cultivation treatments from 2008 to 2009. White clover was sown in the autumn of 2008, and corn was cultivated from June to October 2009 using the four treatments and without any application of chemical herbicides and fertilizers. After the corn harvest, the two treatments of compost application were set up again within each corn cultivation treatment, resulting in a total of eight treatments. Triticale was cultivated in those treatments from October 2009 to June 2010, without chemical herbicides or fertilizers. The results of the treatments showed that LM suppressed weed growth and increased nitrogen (N) uptake and yield of corn compared to the TC treatment. The dry matter yields of corn were the highest and the dry weight of the weeds were the lowest in the LM treatment with compost application before planting. Furthermore, the positive effect of LM on N supply was preserved during the cropping of triticale. Therefore, we concluded that the total dry matter yield of forage crops in corn–triticale rotation could be increased by using white clover LM with compost application to suppress weed growth and to increase the N uptake both of the main and succeeding crops. White clover LM is a useful cultivation technique for organic production of forage crops.