Abstract: In order to study effects of long term K fert ilization on K uptake inWhea-t Corn rotation system, a specifiedfield K fertilizer experiment has been conducted in FarmMalan, Xinji, since autumn of 1992 with 4 treatments that of CK,only provide N and P fertilizer; CK+ wheat straw recycling; Optimum rate of N, P and K fertilizer; N, P and K fert ilization+ wheat straw recycling. All treatments have 4 replications with sequence order. Each plot area is 50 m2.The results asfollowed: K2>O uptake in grain was significant and very significant positively correlated with K2>O fertilization and cropyield.With the increasingly K2/sub>O fertilization, K2/sub>O uptake in grain was become more and more and was not related withthe kind of availible K fertilization.The correlationship between K2/sub>O concentration and K2/sub>O fertilization rate was not siginificant.Under whea-t corn rotat ion system In North China in loamy fluvo-aquic soil, the averages of K2/sub>O concentration inwheat grain was about 4. 99- 5113 g/ kg, and the averages of K2/sub>O concentrat ion in corn grain was about 3175- 3193g/ kg.Under the whea-t corn rotation system and loamy fluvo-aquic soil condition, when gave some external K fert ilizer,therewas little K2/sub>O uptake differences between wheat and corn above ground. The K2/sub>O uptake on wheat was about 140137 kg/ ha, and on corn was about 138123 kg/ ha, hereby can be the guidance of K2/sub>O fertilization.

Key words: Loamy fluvo-aquic soil, Whea-t corn rotation, Long term K_{2/sub>O fertilization,} K uptake

CLC Number: 

• S143.32