The effects of straw-returning and inorganic K fertilizer on the carbon–nitrogen balance and reproductive growth of cotton

Table 3 Changes in leaf N, P and K concentrations for different treatments in 2012 and 2013

Year	Treatment	Peak flower stage (PFS)			Boll-setting stage (BSS)			Boll-opening stage (BOS)
Year	Treatment	K /(mg·kg⁻¹)	N /(mg·kg⁻¹)	P /(mg·kg⁻¹)	K /(mg·kg⁻¹)	N /(mg·kg⁻¹)	P /(mg·kg⁻¹)	K /(mg·kg⁻¹)	N /(mg·kg⁻¹)	P /(mg·kg⁻¹)
2012	CK	29.45 a	32.01 a	3.17 a	13.59 c	25.02 a	2.95 a	8.84 b	16.38 b	2.25 a
	K150	31.24 a	31.65 a	2.98 a	18.55 b	27.04 a	3.23 a	16.09 a	20.29 a	2.54 a
	W9000	34.05 a	29.97 a	3.16 a	21.66 a	27.84 a	3.18 a	18.51 a	21.95 a	2.54 a
2013	CK	23.80 b	37.04 a	3.54 a	10.48 c	26.46 b	2.65 a	9.09 b	15.94 b	2.25 a
	K150	32.83 a	36.80 a	3.40 a	17.42 b	30.33 a	2.82 a	15.81 a	18.68 a	2.31 a
	W9000	30.45 a	35.57 a	3.32 a	21.89 a	29.06 a	2.68 a	16.49 a	20.11 a	2.38 a

CK, no crop straw and K fertilizer were applied as the blank control treatment; K150, 150 k·gha⁻¹ K₂O was applied before transplanting the cotton seedlings; and W9000, 9 000 kg·ha⁻¹ wheat straw was crushed and incorporated in 0∼10 cm soil before transplanting. Values followed by different letters within the same column are significantly different at P = 0.05. Each value represents the mean of three replications

ISSN: 2523-3254