International Journal of Advance Agricultural Research
ISSN: 2053-1265
Vol. 7(1), pp. 1-11, February 2019
doi.org/10.33500/ijaar.2019.07.001

Long-term conservation tillage influences nutrient status in a rice-wheat cropping system

Chaosu Li¹^,2, Xiaoli Wu¹^,2, Miao Liu¹, Ming Li¹, Tao Xiong¹ and Yonglu Tang¹^,2*

¹Crop Research Institute, Sichuan Academy of Agriculture Science, Chengdu 610066, China.
²Provincial Key Laboratory of Water-Saving Agriculture in Hill Areas of Southern China, Chengdu 610066, China.

*To whom correspondence should be addressed. E-mail: xiaoli1755@163.com.

Received 19 December, 2018; Received in revised form 29 January, 2019; Accepted 04 February, 2019.

Abstract

Keywords:
Long-term experiment, Rice-wheat system, Zero tillage, Residue retention, Soil nutrient status, Plant nutrient uptake.

In order to better understand the effects on crop response and soil properties between zero tillage (ZT) and conventional tillage (CT), a long-term field experiment was performed in Southwest China to evaluate how crop production, soil nutrient status and plant nutrient uptake varied under four tillage practices: CT for wheat and rice, CT for rice following, ZT for wheat with residue mulching, CT for rice with half the wheat residue incorporated following, ZT for wheat with residue mulching, ZT for both crops with residue mulching, and ZT plus residue mulching on raised beds. The results obtained show that wheat under ZT had higher yield than CT, whereas the opposite was true for rice. The differences of soil nutrient mainly occurred in topsoil and sub-topsoil between treatments. ZT/residue retention improved soil organic carbon, as well as nitrogen in surface soil, but decreased potassium in topsoil. It was also found that wheat under CT absorbed fewer nutrients than other treatments. While rice under ZT had less nutrient uptake than CT. Partial N balance was negative for all wheat treatments, but positive for rice. N surplus varied (22-82 kg ha^-1 year^-1) across all treatments. More than 30 kg ha^-1 year^-1 P was remaining in the soil because of low absorption. Moreover, residue retention also caused positive K balance. The study indicated that ZT for wheat combined with CT for rice appears optimal for sustainable production.