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 6

Means of meq/100 g K, Ca and Mg and (Ca + Mg) : K ratio in soil and plant.

Treatment	Soil K	Soil Ca	Soil Mg	Plant K	Plant Ca	Plant Mg	(Ca+Mg) : K (soil)	(Ca+Mg) : K (plant)
N92P0K0	0.97^a	0.25^a	0.2^ab	10.04^d	6^d	11.66^a	0.47^ab	1.75^b
N0P50K0	0.98^a	0.25a	0.21^ab	8.8^e	6.83^b	9.16^b	0.48^ab	1.81^b
N0P0K83	1^a	0.233^a	0.19^ab	11.74^c	6.25^cd	8.74^b	0.42^ab	1.27^c
N92P50K0	0.97^a	0.26^a	0.21^ab	8.99^e	6.25^cd	9.58^b	0.48^ab	1.75^b
N92P0K83	1.04^a	0.25^a	0.21^ab	18.14^a	7.08^b	12.91^a	0.44^ab	1.1^cd
N0P50K83	0.99^a	0.26^a	0.21^ab	18.66^a	8.08^a	12.91^a	0.47^ab	1.11^cd
N92P50K83	1^a	0.24^a	0.173^ab	9.38^de	6.58^bcd	9.99^b	0.42^b	1.78^b
I50	0.87^b	0.28^a	0.24^ab	7.21^f	6.75^bc	8.61^b	0.61^ab	2.12^a
M50	0.98^a	0.27^a	0.23^ab	9.35^de	6.75^bc	8.74^b	0.51^ab	1.65^b
I100	0.88^b	0.3^a	0.26^a	7.49^f	6.75^bc	10^b	0.65^a	2.24^a
M100	1.03^a	0.29^a	0.24^ab	16.11^b	7^b	9.99^b	0.51^ab	1.05^d
N0P0K0	1^a	0.23^a	0.17^b	9.51^de	6^d	10^b	0.39^b	1.68^b

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