The effects of straw return on potassium fertilization rate and time in the rice-wheat rotation

• Published in: Soil science and plant nutrition (Tokyo) Vol. 65; no. 2; pp. 176 - 182
• Main Authors: Zhao, Xinlin, Wang, Huoyan, Lu, Dianjun, Chen, Xiaoqin, Zhou, Jianmin
• Format: Journal Article
• Language: English
• Published: Kyoto Taylor & Francis 04.03.2019; Taylor & Francis Ltd
• Subjects: Agricultural practices; Agricultural production; Apparent potassium balance; Cereal crops; Crop rotation; Crop yield; Crops; Dosage; Fertilization; fertilization time; Fertilizer application; fertilizer rates; Fertilizers; field experimentation; Field tests; Oryza; Potassium; potassium application dosage; potassium fertilizers; Rice; Rotation; soil; Soil fertility; soil potassium fertility; Soil treatment; Straw; straw incorporation; Wheat
• DOI: 10.1080/00380768.2018.1564145
• ISSN: 0038-0768; 1747-0765

In order to investigate the effects of straw return on potassium (K) fertilizer application rate and time in the rice-wheat rotation, field experiments were conducted at three sites. The results showed that when the K rate was decreased to 70% of the recommended K dosage, crop yields showed no significant decrease. With K fertilization only at rice phase, crop yields showed no marked difference compared with that provided K fertilizer both at wheat and rice seasons. Though the NH 4 OAc-extracted K and HNO 3 -extracted K differed slightly among the treatments, the soil apparent K balance was negative without K fertilization. With crop straw fully incorporated, the recommended K dosage could be at least reduced by 30% at the experimental sites and the K fertilizer could be applied only at rice phase. A further hypothesis can be made that the best K rate was the amount of K took away by crop grain. In the long run, straw return combined with K fertilization would be an effective method to maintain soil K fertility and productivity.