. 2014 Jul 13;2014:953675. doi: 10.1155/2014/953675

Table 2.

Changes of soil nutrient in plough layer with different regulatory methods. Columns with the same letter represent values that are not significantly different at the 0.05 level of probability according to Duncan's multiple range test. Each value is the mean ± SD (n = 3).

Treatment	Available N (mg kg⁻¹ )			Available P (mg kg⁻¹)			Available K (mg kg⁻¹)
Treatment	2011	2012	2013	2011	2012	2013	2011	2012	2013
CK	53.33 ± 2.50^b l ¹ ¹	61.08 ± 3.26^c	65.43 ± 4.84^c	10.14 ± 0.39^c	9.84 ± 0.37^bc	8.61 ± 0.10^b	75.13 ± 3.96^b	72.35 ± 2.04^b	74.32 ± 4.21^b
Straw mulching	62.38 ± 5.56^a	78.28 ± 3.61^a	90.29 ± 6.53^a	12.91 ± 0.34^a	11.87 ± 0.24^a	9.34 ± 0.17^a	88.88 ± 2.27^a	100.49 ± 8.81^a	107.09 ± 5.58^a
Soil structure conditioner	53.63 ± 1.53^b	70.76 ± 1.71^b	80.44 ± 4.09^b	11.17 ± 0.25^b	9.63 ± 0.50^c	7.14 ± 0.32^c	71.85 ± 4.60^b	70.95 ± 3.19^b	61.61 ± 1.57^c
Water-retaining agent	52.34 ± 2.23^b	65.23 ± 2.62^c	74.14 ± 7.07^bc	10.64 ± 0.41^bc	10.38 ± 0.27^b	8.97 ± 0.09^b	77.76 ± 1.47^b	70.70 ± 3.57^b	77.91 ± 7.25^b