Effect of seed mix, sowing time, summer fallow, site location and aspect on the establishment of sown pasture species on uncultivable hill country

Figures & data

Figure 1. Locations of sites in which a range of pasture establishment methods were compared: Ngaroma (South Waikato, summer-wet), Poukawa (central Hawke’s Bay, summer-dry), Woodville (southern Hawke’s Bay, summer-moist) and Cheviot (North Canterbury, summer-dry).

Figure 2. Monthly rainfall data for each of four sites—Ngaroma, Poukawa, Woodville and Cheviot—from September 2011 to June 2012. The arrows denote when the seed mixes were sown.

Table 1. Site location, climate categorisation, soil type, topography and soil fertility status at the time of sowing for four sites, averaged over the north and south aspects. All sites were located on sheep breeding and finishing farms.

Characteristic	Ngaroma	Poukawa	Woodville	Cheviot
Latitude	−38.270	−39.775	−40.325	−42.825
Longitude	175.565	76.725	175.875	73.275
Climate category	Summer-wet	Summer-dry	Summer-moist	Summer-dry
Long-term 30 yr summer rainfall (mm)	346	154	269	143
Summer rainfall 2011–2012 (mm)^a	432	207	284	197
Total annual rainfall (mm)	1663	712	1176	776
Soil type	Ngaroma silt loam	Matapiro silt loam	Kumeroa hill soils	Amberley Te papa silt loam
Slope angle (°)	28	25	29	28
Olsen phosphate (µg mL^−1)	45	24	31	29
Potassium (MAF QT)^b	6	21	9	18
Sulphate sulphur (ppm)	28	11	8	6
pH (H20)	5.3	6.0	5.5	5.5

^aSummer: December–February.

^bMAF QT (Quick Test) units (Cornforth 1980; Cornforth & Sinclair 1984).

Table 2. Eight treatments applied at each of four sites in New Zealand.

Treatment	Spring 2011		Autumn 2012
	Herbicide applied	Seed mix sown	Herbicide applied	Seed mix sown
Spring sown
Standard-GLH	✓	GLH
Standard-LEG	✓	LEG
Autumn sown
Standard-GLH			✓	GLH
Standard-LEG			✓	LEG
Fallow-GLH	✓		✓	GLH
Fallow-LEG	✓		✓	LEG
Crop-GLH	✓	Summer brassica	✓	GLH
Crop-LEG	✓	Summer brassica	✓	LEG

GLH, grasses, legumes and herbs; LEG, legumes only.

Seed mixes were sown in spring or autumn.

Herbicide was applied only in spring or autumn before sowing in the standard treatment, and in both spring and the following autumn for the ‘summer fallow’ and ‘summer crop’ treatments.

Table 3. Sowing rate, seed weight, germination percentage and germinable seed density of species included in the grasses, legumes and herbs seed mix and legume only seed mix sown in a range of treatments at four sites throughout New Zealand.

Seed mix	Species	Sowing rate (kg ha^−1)	Seed weight (g 1000 seeds^−1)	Seed weight sown (g m^−2)	Sown seed density (seeds m^−2)	Germination (%)	Germinable seed density (seeds m^−2)
GLH	Perennial ryegrass	7.0	2.0	0.70	350	96	336
	Cocksfoot	1.5	0.9	0.15	167	92	153
	Phalaris	1.5	2.0	0.15	75	94	71
	Grazing brome	8.0	11.5	0.80	70	89	62
	Chicory	0.5	1.2	0.05	42	92	38
	Plantain	0.5	2.0	0.05	25	90	23
	White clover	2.0	0.7	0.20	286	98	280
	Red clover	3.0	3.4	0.30	88	97	86
	Sub clover	4.0	6.7	0.40	60	98	59
	Total	28.0		2.80	1163		1108
LEG	White clover	1.0	0.7	0.10	143	98	140
	Red clover	4.6	3.4	0.46	135	97	131
	Sub clover	9.3	6.7	0.93	139	98	136
	Birdsfoot trefoil	1.6	1.2	0.16	133	90	120
	Lotus	0.7	0.5	0.07	140	91	127
	Total	17.2		1.72	690		654

GLH, grasses, legumes and herbs; LEG, legumes only.

Table 4. Effects of aspect (north, south), seed mix, season (sown in spring or autumn) and summer fallow (with or without) on percentage establishment (% of germinable seed sown) for each of the sown grasses, legumes and herbs.

Establishment (%)	Aspect^a				Seed mix^a				Season^a				Fallow^b
	North	South	SED	F prob	GLH	LEG	SED	F prob	Spring	Autumn	SED	F prob	No	Yes	SED	F prob
Perennial ryegrass	18	31	4.0	0.043	24	–			13	36	9.8	0.032	36	22	7.6	0.075
Cocksfoot	2	3	1.2	ns	2	–			2	3	1.1	ns	3	7	0.7	<0.001
Phalaris	12	4	8.7	ns	8	–			6	9	3.7	ns	9	11	3.5	ns
Grazing Brome	13	5	10.3	ns	9	–			7	11	6.4	ns				–^c
White clover	10	14	1.8	ns	8	17	2.9	0.004	12	13	2.9	ns	13	26	2.8	<0.001
Red clover	16	22	7.5	ns	25	14	5.5	0.041	25	14	5.5	0.067	14	17	2.3	ns
Subterranean clover	5	6	1.9	ns	7	4	1.1	0.005	7	5	1.1	ns	5	7	1.8	ns
Lotus	4	6	1.0	0.087	–	5			6	3	1.5	0.041	3	8	1.4	0.002
Birdsfoot trefoil	4	5	0.3	0.042	–	5			4	6	1.4	0.097	6	10	1.4	0.017
Chicory	9	11	3.4	ns	10	–			13	7	2.7	0.063	7	12	2.4	0.040
Plantain	14	29	8.3	ns	22	–			26	18	8.4	ns	18	35	5.7	0.005
Sown grasses	13	18	2.1	0.068	16	–			9	22	5.7	0.030	22	15	4.2	ns
Sown legumes	8	11	1.3	ns	11	8	2.0	0.073	11	8	2.0	ns	8	14	1.2	<0.001
Sown herbs	11	18	5.1	ns	14	–			17	11	4.6	ns	11	21	3.2	0.007
Total sown	9	13	1.3	0.073	14	8	2.5	0.017	10	12	2.5	ns	12	14	1.8	ns

GLH, grasses, legumes and herbs; LEG, legumes only; SED, standard error of difference.

‘–’ denotes species not sown; ‘ns’ denotes means not significantly different (P  > 0.1).

Means in bold are significantly different (P  < 0.05).

Assessments were made 6–8 weeks after sowing.

Results are based on ANOVA of four sites.

^aData from the ‘standard’ treatment are used for aspect, seed mix and season comparisons because it was the only treatment sown in both autumn and spring.

^bComparison of standard vs fallow treatments sown in autumn.

^cSeedling densities were low and there were insufficient data to be analysed.

Table 5. Significant first-order interactions between aspect (north, south) and seed mix, season (sown in spring or autumn) or summer fallow (with or without) on percentage establishment (% of germinable seed sown) of sown grasses, legumes and herbs.

Interaction	Site	Species	North aspect		South aspect		SED	F prob
Aspect × seed mix			GLH	LEG	GLH	LEG
	Woodville	White clover	10	16	19	39	8.8	0.024
Aspect × season^a			Spring	Autumn	Spring	Autumn
	All sites	Red clover	17	12	33	12	15.6	0.048
	Ngaroma	Subterranean clover	<1	<1	7	<1	1.3	<0.001
	Woodville	White clover	30	6	22	15	9.0	0.010
		Subterranean clover	8	<1	2	5	3.8	<0.001
		Birdsfoot trefoil	10	1	3	11	3.3	<0.001
	Cheviot	Grazing brome	1	79	1	1	15.7	<0.001
		Red clover	5	43	23	8	15.2	<0.001
		Sown legumes	3	14	11	5	4.3	<0.001
		Chicory	6	12	10	3	3.2	<0.001
		Sown herbs	5	12	9	5	3.5	0.008
		Total sown	2	15	7	10	3.7	<0.001
Aspect × fallow^b			No fallow	Fallow	No fallow	Fallow
	All sites	Lotus	3	4	4	12	2.7	0.024
	Poukawa	Sown herbs	27	21	42	21	9.6	0.007
		Total sown	22	18	29	14	5.9	0.007
	Woodville	Perennial ryegrass	3	7	8	28	5.6	0.009
		Cocksfoot	1	2	<1	7	2.1	0.014
		Sown grasses	2	5	5	17	3.7	0.017
		White clover	6	20	15	43	8.8	0.039
		Lotus	<1	2	5	12	2.2	0.049
		Plantain	<1	<1	10	47	8.6	<0.001
		Sown herbs	2	10	8	26	4.1	0.013
		Total sown	2	7	8	19	3.4	0.021
	Cheviot	Phalaris	2	3	5	14	3.0	0.012
		Grazing brome	79	35	<1	<1	19.6	0.034
		Lotus	3	4	6	23	4.6	0.002
		Birdsfoot trefoil	7	8	6	17	4.0	0.030
		Sown legumes	14	15	5	20	5.0	<0.001
		Total sown	15	14	10	19	4.3	0.002

GLH, grasses, legumes and herbs; LEG, legumes only; SED, standard error of difference for comparisons within an aspect.

Assessments were made 6–8 weeks after sowing.

Means in bold are significantly different for comparisons within an aspect within each row (P  < 0.05).

SED and F prob values are for the interactions between aspect × seed mix, aspect × season and aspect × fallow.

^aComparison of standard treatments only.

^bAutumn sown treatments only.

Table 6. Effects of season (sown in spring or autumn), summer fallow (with or without) and seed mix on percentage establishment (% of germinable seed sown) for each of the sown grasses, legumes and herbs.

Season	Spring 2011		Autumn 2012
Herbicide application	Standard		Standard		Fallow		Crop
Seed mix	GLH	LEG	GLH	LEG	GLH	LEG	GLH	LEG	SED	F prob
Perennial ryegrass	13b	–	36a	–	22a,b	–	24a,b	–	8.7	0.023
Cocksfoot	2b	–	3b	–	7a	–	7a	–	1.1	<.001
Phalaris	6	–	9	–	11	–	14	–	3.8	ns
Grazing brome	7	–	11	–	7	–	5	–	5.5	ns
White clover	10b,c	14b,c	6c	19b	16b	37a	14b,c	33a	4.8	0.023
Red clover	33	16	18	11	21	13	23	13	7.5	ns
Subterranean clover	8	5	6	3	10	5	14	4	2.8	ns
Lotus	–	6a,b	–	3b	–	8a	–	7a	2.0	0.046
Birdsfoot trefoil	–	4c	–	6b,c	–	10a	–	8a,b	1.7	<.001
Chicory	13	–	7	–	12	–	13	–	2.7	0.058
Plantain	26	–	18	–	35	–	34	–	8.1	0.062
Sown grasses	9b	–	22a	–	15a,b	–	17a,b	–	5.0	0.023
Sown legumes	14	8	8	7	16	13	16	11	2.0	ns
Sown herbs	17a,b	–	11b	–	21a	–	20a	–	4.4	0.050
Total sown	11	8	16	7	16	13	17	11	3.3	ns

GLH, grasses, legumes and herbs; LEG, legumes only; SED, standard error of difference for comparisons within each row.

‘–’ denotes species not present; ‘ns’ denotes not significantly different (P > 0.1).

Means in bold with different subscripts are significantly different for comparisons within a row (P < 0.05).

Results are based on ANOVA of four sites and are averaged over aspects.

Assessments were made 6–8 weeks after sowing.

Table 7. Effects of seed mix, season (sown in spring or autumn) and summer fallow (with or without) on percentage establishment (% of germinable seed sown) of sown grasses, legumes and herbs at four sites.

Site	Establishment (%)	Seed mix^a				Season^a				Fallow^b
		GLH	LEG	SED	F prob	Spring	Autumn	SED	F prob	No	Yes	SED	F prob
Ngaroma	Perennial ryegrass	16	–			16	15	2.8	ns	15	19	3.4	ns
	Cocksfoot	3	–			5	1	0.7	<0.001	1	8	1.4	<.001
	Phalaris	4	–			5	2	1.9	ns	2	12	2.8	0.002
	Grazing brome	3	–			4	1	1.2	0.008	1	3	1.6	ns
	White clover	4	10	1.6	<0.001	10	4	1.6	<0.001	4	19	2.5	<0.001
	Red clover	10	8	1.6	ns	15	3	1.6	<0.001	3	18	2.0	<0.001
	Subterranean clover	2	2	0.5	ns	5	0	0.5	<0.001				-^c
	Lotus	–	5			7	3	1.9	ns	3	5	1.8	ns
	Birdsfoot trefoil	–	6			5	8	3.4	ns	8	8	3.4	ns
	Chicory	11	–			18	4	1.8	<0.001	4	16	2.6	<0.001
	Plantain	18	–			31	5	5.2	<0.001	5	41	6.6	<0.001
	Sown grasses	10	–			11	9	1.8	ns	9	14	2 . 2	0.028
	Sown legumes	5	6	0.8	ns	8	2	0 . 8	<0.001	3	11	1 . 1	<0.001
	Sown herbs	13	–			23	4	2 . 6	<0.001	4	25	3 . 6	<0.001
	Total sown	8	6	0 . 9	0.009	9	5	0 . 9	<0.001	5	11	1 . 1	<0.001
Poukawa	Perennial ryegrass	52	–			9	94	10.9	<0.001	94	29	9.3	<0.001
	Cocksfoot	5	–			2	8	0.7	<0.001	8	11	1.5	ns
	Phalaris	24	–			18	30	11.0	ns	30	19	10.0	ns
	Grazing brome	5	–			10	1	1.6	<0.001				-^c
	White clover	8	22	4.6	0.005	4	26	4.6	<0.001	26	29	5.0	ns
	Red clover	14	9	3.1	0.086	5	18	3.1	<0.001	18	11	2.9	0.019
	Subterranean clover	15	8	3.2	0.020	11	12	3.2	ns	12	13	5.2	ns
	Lotus	–	3			3	3	1.0	ns	3	7	1.9	0.077
	Birdsfoot trefoil	–	2			2	3	0.8	0.093	3	11	2.5	0.004
	Chicory	10	–			7	13	4.7	ns	13	8	4.2	ns
	Plantain	32	–			13	50	6.5	<0.001	50	42	9.5	ns
	Sown grasses	33	–			9	57	6 . 0	<0.001	57	21	5 . 2	<0.001
	Sown legumes	10	8	1.7	0.155	5	13	1 . 7	<0.001	13	14	2.0	ns
	Sown herbs	18	–			9	27	4 . 5	<0.001	27	21	4.8	ns
	Total sown	23	8	2 . 2	<0.001	6	25	2 . 2	<0.001	25	16	2 . 1	<0.001
Woodville	Perennial ryegrass	15	–			25	5	3.6	<0.001	5	17	2.8	<0.001
	Cocksfoot	1	–			1	1	0.3	0.045	1	4	1.1	0.001
	Phalaris				-^c				-^c				-^c
	Grazing brome	8	–			11	4	2.2	0.006	4	6	2.5	ns
	White clover	13	23	3.2	0.006	26	10	3.2	<0.001	10	32	3.1	<0.001
	Red clover	51	23	4.7	<0.001	64	10	4.7	<0.001	10	13	2.3	ns
	Subterranean clover	6	2	1.3	0.004	5	2	1.3	0.050	2	3	1.2	ns
	Lotus	–	9			15	3	2.5	<0.001	3	7	1.1	<0.001
	Birdsfoot trefoil	–	6			6	6	1.6	ns	6	6	0.9	ns
	Chicory	12	–			18	5	3.0	<0.001	5	13	2.1	<0.001
	Plantain	30	–			53	6	4.6	<0.001	6	26	4.3	<0.001
	Sown grasses	9	–			15	4	2 . 0	<0.001	4	11	1 . 9	<0.001
	Sown legumes	20	11	1 . 9	<0.001	25	6	1 . 9	<0.001	6	15	1 . 6	<0.001
	Sown herbs	18	–			31	5	3 . 1	<0.001	5	18	2 . 1	<0.001
	Total sown	14	11	1 . 3	0.026	19	5	1 . 3	<0.001	5	13	1 . 2	<0.001
Cheviot	Perennial ryegrass	15	–			2	29	5.1	<0.001	29	22	4.4	ns
	Cocksfoot	1	–			0	1	0.5	ns	1	6	1.2	<0.001
	Phalaris	2	–			1	3	1.7	ns	3	8	1.5	0.003
	Grazing brome	20	–			1	40	7.9	<0.001	40	18	9.8	0.036
	White clover	7	13	2.1	0.005	9	10	2.1	ns	10	27	3.1	<0.001
	Red clover	25	14	5.4	0.048	14	26	5.4	0.037	26	27	4.7	ns
	Subterranean clover	6	4	1.4	ns	5	5	1.4	ns	5	13	3.1	0.008
	Lotus	–	3			1	5	1.5	0.053	5	14	2.3	<0.001
	Birdsfoot trefoil	–	4			2	6	1.4	0.002	6	13	2.0	0.004
	Chicory	8	–			8	8	1.6	ns	8	12	3.0	ns
	Plantain	8	–			5	10	2.7	ns	10	31	7.7	0.010
	Sown grasses	11	–			1	20	3 . 0	<0.001	20	16	2.7	ns
	Sown legumes	10	7	1 . 5	0.025	7	10	1.5	ns	10	17	1 . 8	<0.001
	Sown herbs	8	–			7	8	1.8	ns	8	19	4 . 3	0.021
	Total sown	10	7	1 . 3	0.009	5	12	1 . 3	<0.001	12	17	1 . 5	0.003

GLH, grasses, legumes and herbs; LEG, legumes only; SED, standard error of difference for comparisons within seed mix, season or fallow.

‘–’ denotes species not present; ‘ns’ denotes means not significantly different (P  > 0.1).

Means in bold are significantly different (P  < 0.05).

Results are averaged over aspects. Assessments were made 6–8 weeks after sowing.

Ngaroma: 1663 average annual rainfall, 346 average summer rainfall, silt loam soils; Poukawa: 712 mm, 154 mm, silt loam soils; Woodville: 1176 mm, 269 mm, hill soils; Cheviot: 776 mm, 143 mm, silt loam soils.

^aData from the ‘standard’ treatment are used for aspect, seed mix and season comparisons because it was the only treatment sown in both autumn and spring.

^bComparison of standard vs fallow treatments sown in autumn.

^cSeedling densities were low and there were insufficient data to be analysed.

Table 8. Effect of season (sown in spring or autumn), summer fallow (with or without) and seed mix on percentage establishment (% of germinable seed sown) of sown grasses, legumes and herbs at four sites.

	Season	Spring 2011		Autumn 2012
	Herbicide application	Standard		Standard		Fallow		Crop
Site	Seed mix	GLH	LEG	GLH	LEG	GLH	LEG	GLH	LEG	SED	F prob
Ngaroma	Perennial ryegrass	16b	–	15b	–	19b	–	27a	–	3.8	0.028
	Cocksfoot	5b	–	1c	–	8a	–	8a	–	1.5	<.001
	Phalaris	5b	–	2b	–	12a	–	11a	–	2.9	<.001
	Grazing brome	4a,b	–	1b	–	3b	–	7a	–	1.8	0.012
	White clover	7	13	1	6	10	27	9	17	6.4	ns
	Red clover	16b,c	15b,c	4d,e	2e	24a,b	13c,d	28a	14c	4.9	0.015
	Subterranean clover	0	0	0	0	0	0	0	0	–	–
	Lotus	–	7	–	3	–	5	–	2	2.3	0.095
	Birdsfoot trefoil	–	5	–	8	–	8	–	8	3.5	ns
	Chicory	18a	–	4b	–	16a	–	17a	–	3.0	<.001
	Plantain	31a	–	4b	–	41a	–	41a	–	8.0	<.001
	Sown grasses	11b,c	–	9c	–	14a,b	–	18a	–	2.5	0.002
	Sown legumes	8	8	2	3	12	9	12	7	2.7	ns
	Sown herbs	22a	–	4b	–	25a	–	26a	–	4.2	<.001
	Total sown	11	8	6	3	14	9	16	7	2.6	0.063
Poukawa	Perennial ryegrass	9b	–	94a	–	29b	–	28b	–	10.1	<.001
	Cocksfoot	2b	–	8a	–	11a	–	11a	–	1.7	<.001
	Phalaris	18	–	30	–	19	–	36	–	11.4	ns
	Grazing brome	0	0	0	0	0	0	0	0	–	–
	White clover	3c	5c	13c	39a,b	15c	42a	17b,c	40a	11.1	0.023
	Red clover	6	4	23	13	15	7	14	9	6.5	ns
	Subterranean clover	15	8	16	8	14	11	39	11	10.8	ns
	Lotus	–	3c	–	3c	–	7b	–	12a	2.0	<.001
	Birdsfoot trefoil	–	2b	–	3b	–	11a	–	9a	2.8	<.001
	Chicory	7	–	13	–	8	–	7	–	4.9	ns
	Plantain	13b	–	50a	–	42a	–	54a	–	10.1	<.001
	Sown grasses	9c	–	57a	–	21b	–	22b	–	5.6	<.001
	Sown legumes	5	4	15	12	15	14	19	14	4.3	ns
	Sown herbs	9b	–	27a	–	21a	–	24a	–	5.6	0.003
	Total sown	7b,c	4c	39a	12b,c	18b	14b	21b	14b	4.7	<.001
Woodville	Perennial ryegrass	25a	–	5c	–	17a,b	–	12b,c	–	4.3	<.001
	Cocksfoot	1b	–	1b	–	4a	–	2a,b	–	1.1	<.001
	Phalaris	0	–	0	–	0	–	0	–	–	–
	Grazing brome	11a	–	4b	–	6a,b	–	3b	–	3.2	0.028
	White clover	22	29	5	16	24	39	13	38	8.5	ns
	Red clover	92a	36b	10c	11c	17c	8c	17c	11c	9.3	<.001
	Subterranean clover	7	3	5	0	4	2	3	0	2.7	ns
	Lotus	–	15a	–	3c	–	7b,c	–	8b	2.4	<.001
	Birdsfoot trefoil	–	6	–	6	–	6	–	7	1.6	ns
	Chicory	18a	–	5c	–	13a,b	–	10b,c	–	3.1	<.001
	Plantain	53a	–	6c	–	26b	–	14b,c	–	6.4	<.001
	Sown grasses	15a	–	3c	–	11a,b	–	8b,c	–	2.7	<.001
	Sown legumes	34a	15b,c	6c	6c	20b	11b,c	13b,c	11b,c	4.7	<.001
	Sown herbs	31a	–	5c	–	18b	–	12b	–	3.5	<.001
	Total sown	23a	15b	5c	6c	15b	11b,c	10b,c	11b,c	3.4	0.004
Cheviot	Perennial ryegrass	2b	–	29a	–	22a	–	30a	–	4.9	<.001
	Cocksfoot	<1b	–	1b	–	6a	–	7a	–	1.3	<.001
	Phalaris	1b	–	3b	–	8a	–	9a	–	2.4	<.001
	Grazing brome	1b	–	40a	–	18b	–	10b	–	10.6	<.001
	White clover	8b	10b	5b	15b	14b	40a	18b	38a	7.1	<.001
	Red clover	17	11	34	18	29	25	34	17	11.0	ns
	Subterranean clover	7b	4b	5b	5b	22a	5b	14a,b	6b	6.6	0.017
	Lotus	–	1b	–	5b	–	14a	–	5b	2.6	<.001
	Birdsfoot trefoil	–	2c	–	6b,c	–	13a	–	10a,b	2.2	<.001
	Chicory	8b	–	8b	–	12a,b	–	18a	–	3.3	0.016
	Plantain	5b	–	10b	–	31a	–	24a,b	–	7.8	<.001
	Sown grasses	1b	–	20a	–	16a	–	20a	–	3.1	<.001
	Sown legumes	10	5	11	8	18	17	20	13	4.2	ns
	Sown herbs	7b	–	8b	–	19a	–	20a	–	4.6	0.002
	Total sown	5d	5d	16a,b	8c,d	17a,b	17a,b	20a	13b,c	3.5	0.018

GLH, grasses, legumes and herbs; LEG, legumes only; SED, standard error of difference for comparisons within each row.

‘–’ denotes species not present; ‘ns’ denotes not significantly different (P  > 0.1).

Means in bold with different subscripts are significantly different for comparisons within a row (P  < 0.05).

Results are averaged over aspects.

Assessments were made 6–8 weeks after sowing.

Ngaroma: 1663 average annual rainfall, 346 average summer rainfall, silt loam soils; Poukawa: 712 mm, 154 mm, silt loam soils; Woodville: 1176 mm, 269 mm, hill soils; Cheviot: 776 mm, 143 mm, silt loam soils.

Figure 3. Mean soil temperature at 10 cm depth at 0900 h for each of four sites: Ngaroma, Poukawa, Woodville and Cheviot. The means are calculated from all data from the time of sowing until the time of counting for each site for each aspect × season combination.

Cornforth IS. 1980. Soil and fertilisers: Soil analysis – interpretation. AgLink AST 8. Wellington: New Zealand Ministry of Agriculture and Fisheries; p. 3.

 Google Scholar

Cornforth IS, Sinclair AG. 1984. Fertiliser and lime recommendations for pastures and crops in New Zealand. (Second revised edition.) Wellington: New Zealand Ministry of Agriculture and Fisheries; p. 66.

 Google Scholar