Ammonia exchange on grasslands in an intensive dairying region in central Japan

Figures & data

Table 1 Application rates of nitrogen (kg N ha−1)

Year	Treatment	March	May	July	September	November	Total N	Total NH4-N
2006	Manure	30	54	45	27	124^†	155 + 124^†	155 + 0.97
	Fertilizer	59	59	50	27		198	59
2007	Manure	31	54	31	40 + 253^†		157 + 253^†	157 + 8.45
	Fertilizer	60	54	32	40		186	56
2008	Manure	29	40	40	29	218^†	139 + 218^†	139 + 8.43
	Fertilizer	60	51	51	29		189	57
^†Composted manure.

Table 2 Forage yield (Mg ha−1 dry matter)

Year	Cutting	Date	Yield
			Manure	Fertilizer
2006	First	16 May	4.4 (1.1)	3.5 (1.5)	*
	Second	5 July	3.1 (0.3)	2.8 (0.5)	n.s.
	Third	28 August	1.2 (0.3)	1.4 (0.3)	n.s.
	Fourth	7 November	1.1 (0.3)	1.4 (0.3)	**
	Total		9.6	9.0
2007	First	27 May	3.1 (0.8)	3.5 (2.2)	n.s.
	Second	24 July	3.0 (0.3)	2.7 (0.6)	n.s.
	Third	1 September	2.6 (0.4)	2.4 (0.4)	n.s.
	Total		8.6	8.6
2008	First	15 May	4.1 (0.7)	5.5 (1.4)	**
	Second	8 July	4.0 (0.6)	4.1 (0.9)	n.s.
	Third	27 August	1.6 (0.3)	2.1 (0.1)	*
	Fourth	5 November	1.3 (0.4)	0.9 (0.2)	*
	Total		10.9	12.6
*P < 0.05; **P < 0.01. Values in parentheses are the standard deviations.

Table 3 Soil chemical properties

Year	Soil layer (cm)	pH		Bray-P (mg 100 g^−1)		Ex-K (mg 100 g^−1)		Ex-Ca (mg 100g^−1)		Ex-Mg (mg 100 g^−1)
		Manure	Fertilizer	Manure	Fertilizer	Manure	Fertilizer	Manure	Fertilizer	Manure	Fertilizer
2007	0–5	6.11	6.02	49.3**	34.6**	29.5	23.3	77.0**	42.1**	18.2**	10.4**
	5–10	5.88	6.26	21.8**	11.8**	6.8	7.0	21.9**	48.2**	4.0**	7.6**
	10–15	5.81	5.90	24.3	16.0	11.0	11.0	37.4	39.6	7.5	7.3
2008	0–5	6.30	6.05	30.2**	20.4**	8.7	8.7	117.0***	60.0***	27.1	18.2
	5–10	6.28	5.99	26.5**	16.8**	6.0	6.2	110.8***	52.5***	24.7***	13.7***
	10–15	6.13**	5.77**	27.0***	15.5***	6.9	5.5	107.5***	41.5***	17.2***	8.0***
Year	Soil layer (cm)	NO3-N (mg 100 g^−1)		NH4-N (mg 100 g^−1)		T-N (%)		T-C (%)		CEC (cmol kg^−1)
		Manure	Fertilizer	Manure	Fertilizer	Manure	Fertilizer	Manure	Fertilizer	Manure	Fertilizer
2007	0–5
	5–10
	10–15
2008	0–5	0.7	0.5	1.9	1.8	0.33	0.27	4.18	3.72	21.05*	17.87*
	5–10	0.5	0.3	1.5	1.7	0.31	0.27	3.96	3.70
	10–15	0.6	0.4	1.7	1.7	0.32	0.25	4.11	3.54
*P < 0.10; **P < 0.05; ***P < 0.01.

Figure 1 Seasonal variations in the atmospheric concentration of NH3 from March 2006 to March 2007 in the (a) manure and (b) fertilizer plots. Upper, 2.4 m height; lower, 0.7 m height; ‘Particle’, the averaged value of particle ammonium at 2.4 m height and 0.7 m height. The arrows with no sign show the timing of the chemical fertilizer application and the arrow with ‘M’ refers to the application of manure.

Figure 2 Seasonal variations in NH3 flux and soil temperature in (a) 2006–2007, (b) 2007–2008 and (c) 2008–2009. The arrows with no sign show the timing of the chemical fertilizer application and the arrow with ‘M’ refers to the application of manure.

Figure 3 Seasonal variations in NH3 flux from March 2006 to March 2007. The vertical scale between −20 and +20 g N ha−1 h−1 has been magnified. The arrows with no sign show the timing of the chemical fertilizer application and the arrow with ‘M’ refers to the application of manure.

Table 4 Annual balance of ammonia fluxes (kg N ha−1 year−1)

Treatment	2006–2007			2007–2008			2008–2009			2006–2009		Annual average	†
	Balance	Emission	Deposition	Balance	Emission	Deposition	Balance	Emission	Deposition	Emission	Deposition	Balance
Manure	−10.1	8.5	−18.6	−13.6	8.3	−22.0	−19.3	3.6	−22.9	20.5	−63.5	−14.4	4.6
(% of NH4-N)		5.4			5.1			2.5		4.4
(% of T-N)		3.0			2.0			1.0		2.0
Fertilizer	−20.4	4.3	−24.8	−20.6	9.4	−29.9	−15.0	6.3	−21.3	20.0	−76.0	−18.6	3.2
(% of NH4-N)		7.3			16.8			11.0			11.6
(% of T-N)		2.2			5.0			3.3			3.5
^†Indicates standard deviation.