Effects of Paper-Mill Sludge as a Mulch versus Topsoil Incorporation on Potassium Uptake and the Grain Yield of Rain-Fed Wheat in a High Specific Surface Loess Soil with Illite Dominance in Clay Fraction

Table 5

Soil nutrient concentrations at harvest.

Treatment	NO3-N (mg kg^−1)	NH4-N (mg kg^−1)	Organic C (%)	Total N (%)	Avai. P (mg kg^−1)	Avai. K (mg kg^−1)	Ext. Ca (meq l^−1)	Ext. Mg (meq l^−1)	EC (dS m^−1)	pH	C/N
N92P0K0	38.8^a	0.1^d	1.25^e	0.12^e	18.06^d	380^b	5.1^a	4.1^a	0.46^b	7.55^abcd	10.41^ab
N0P50K0	7.66^d	0.12^d	1.23^e	0.12^e	24^c	385.6^ab	5.23^a	4.3^a	0.58^ab	7.54^abcd	10.26^ab
N0P0K83	18^c	0.15^c	1.31^de	0.13^e	15.7^d	392^ab	4.8^a	3.8^a	0.58^ab	7.45^cd	10.07^abc
N92P50K0	30.6^b	0.1^d	1.17^e	0.12^e	27.3^bc	380^b	5.2^a	4.2^a	0.67^a	7.55^abcd	9.77^bcde
N92P0K83	22^c	0.12^d	1.19^e	0.13^e	14.9^d	407.6^a	5.1^a	4.2^a	0.59^ab	7.75^a	9.15^e
N0P50K83	18^c	0.15^c	1.37^de	0.14^e	35.6^a	387.3^ab	5.33^a	4.3^a	0.51^ab	7.62^abc	9.8^bcde
N92P50K83	36^a	0.15^c	1.3^de	0.14^e	27^bc	394^ab	5^a	4^a	0.47^b	7.69^ab	9.27^de
I50	7.33^d	0.22^b	2.39^b	0.23^b	17.36^d	340.3^c	5.66^a	4.96^a	0.51^ab	7.48^bcd	10.41^ab
M50	9.3^d	0.12^d	1.48^d	0.16^d	17.23^d	383.6^ab	5.5^a	4.73^a	0.45^b	7.57^abc	9.26^de
I100	9.3^d	0.27^a	2.86^a	0.27^a	17.1^d	346.6c	6.16^a	5.2^a	0.59^ab	7.52^abcd	10.6^a
M100	10^d	0.2^b	1.81^c	0.19^c	30.1^ab	405.3^ab	6^a	4.8^a	0.66^a	7.5^bcd	9.52^cde
N0P0K0	10.33^d	0.1^d	1.2^e	0.12^e	16.9^d	393.3^ab	4.66^a	3.5^a	0.46^b	7.33^d	10^abcd

Means within the same column followed by the same letter are not statistically different at 𝑃=0.05 (Fisher’s LSD).