Crop Residue Biomass Effects on Agricultural Runoff

Table 3

Biomass residue and field length effects on soluble P, NO₃⁻-, and NH₄⁺- in the 274 m long field. Shown are means (standard error), as well as analysis of variance results. 𝑛=3.

Location (m)	Treatment	Soluble P conc; (mg L^−1)	Soluble P exp; (kg ha^−1)	NO3^− conc; (mg L^−1)	NO3^− exp; (kg ha^−1)	NH4^+ conc; (mg L^−1)	NH4^+ exp; (kg ha^−1)
91	Control	0.06 (0.01)^b	0.14 (0.03)	2.46 (0.20)^c	9.60 (1.36)^b	0.11 (0.03)^b	0.36 (0.06)
	Low	0.07 (0.02)^b	0.23 (0.10)	3.27 (0.19)^b	10.07 (1.35)^b	0.18 (0.11)^b	0.48 (0.31)
	Medium	0.09 (0.03)^b	0.25 (0.06)	3.70 (0.38)^ab	12.80 (2.40)^b	0.16 (0.09)^b	0.41 (0.18)
	High	0.20 (0.05)^a	0.35 (0.09)	3.32 (0.31)^a	6.50 (0.86)^a	0.22 (0.10)^a	0.36 (0.15)
183	Control	0.08 (0.01)^y	0.06 (0.02)	2.69 (0.21)^z	2.20 (0.10)^y	0.13 (0.02)^y	0.08 (0.03)
	Low	0.11 (0.03)^y	0.07 (0.02)	3.73 (0.27)^y	2.60 (0.45)^y	0.21 (0.10)^y	0.09 (0.03)
	Medium	0.24 (0.11)^y	0.06 (0.01)	4.62 (0.80)^xy	1.73 (0.56)^y	0.45 (0.25)^y	0.10 (0.02)
	High	0.74 (0.23)^x	0.07 (0.03)	5.40 (0.34)^x	0.57 (0.19)^x	1.32 (0.50)^x	0.09 (0.04)
Analysis of variance
	Biomass	**	NS	**	*	*	NS
	Length	*	***	**	***	*	**
	Biomass × lenght	*	NS	NS	NS	*	NS

For each variable and length, values designated with the same letter are not significantly different.