. 2019 Aug 13;9:11776. doi: 10.1038/s41598-019-48207-z

Table 2.

Soil nitrogen fractions (CWEN, cold water extractable nitrogen; HWEN, hot water extractable nitrogen; AEN, acid extractable nitrogen) as impacted by long-term manure and fertilizer treatments for 0–7.5 cm depth at soybean planting (P), one month after soybean planting (1MAP) and at soybean harvest.

Treatments	CWEN			HWEN			AEN
	------------------------------------------(g kg ^-1 ) --------------------------------------------
	P	1MAP	H	P	1MAP	H	P	1MAP	H
LM^††	0.039^b†	0.043^b	0.024^b	0.100^cb	0.147^b	0.126^cb	1.632^ac	1.994^ns	1.567^b
MM	0.045^b	0.032^b	0.041^a	0.116^b	0.114^cb	0.142^b	1.862^ba	1.669	2.134^a
HM	0.091^a	0.137^a	0.048^a	0.206^a	0.190^a	0.187^a	2.060^a	1.598	2.165^a
MF	0.037^b	0.034^b	0.020^b	0.072^d	0.074^ed	0.094^cd	1.747^ba	1.519	1.239^b
HF	0.041^b	0.043^b	0.017^b	0.079^cd	0.107^cd	0.087^d	1.179^c	1.716	1.522^b
CK	0.029^b	0.035^b	0.015^b	0.075^cd	0.064^e	0.078^d	1.473^bc	1.382	1.483^b
	Analysis of Variance (P > F)
Treatment	0.003	0.001	0.003	<0.0001	<0.0001	0.0001	0.0224	0.1396	0.0023
M vs. F	0.034	0.016	0.002	<0.0001	0.0006	0.0006	0.0694	0.2505	0.0003

^†Mean values followed by different lower letters between each treatment within each sampling time represent significant differences due to manure and inorganic fertilizer application at P < 0.05. ^††LM, low manure rate based on recommended phosphorus rate; MM, medium manure rate based on recommended nitrogen rate; HM, high manure rate based on double of the recommended nitrogen rate; MF, recommended fertilizer; HF, high fertilizer; and CK, control with no manure application. ns, no significant.