Pasture growth and soil fertility: VIII. the influence of grasses, white clover, fertilisers, and the return of herbage clippings on pasture production of an impoverished soil

Sears, P. D.; Goodall, V. C.; Jackman, R. H.; Robinson, G. S.

doi:10.1080/00288233.1965.10422357

Cited by 45 publications

(23 citation statements)

References 6 publications

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“…The annual turnover of N in measured herbage averaged 433 kglha (range 250-690 kg N/ha), a figure comparable with those reported by Sears et al (1965) for grass-clover mixtures, over the final 3 years of their study. This average value, while lower than a figure of 720 kg N/ha reported by Ball et al (1979) at Palmers ton North, is considerably greater than the N turnover in southern England grass-clover pasture (295 kglha, Whitehead 1970).…”

Section: Discussionsupporting

confidence: 73%

“…The average value obtained in this trial for fixation efficiency is almost identical to that obtained by Sears et al (1965) in their treatments with simulated return of animal excreta. In view of the different approaches taken in the two studies (N balance calculations, and direct measurement in this study), the concurrence increases confidence in this field application of the acetylene reduction assay.…”

Section: Discussionsupporting

confidence: 66%

“…Soil N contents (0-15 cm) averaged 0.30% (range 0.18-0.43%) and soil C averaged 3.50% (range 1.64-5.42%) compared with 0.12-0.14% N and 1.1-1.2% C at the site used by Sears et al (1965). Relationships between production, climate, and soil variables Correlation analyses were carried out on annual and seasonal data to test for general relationships between production, climate, and soil characteristics.…”

Section: Soilsmentioning

confidence: 99%

“…Earlier work by Sears et al (1965) at Palmerston North, using a pasture development sequence initiated on a raw subsoil, indicated potential annual nitrogen fixation inputs of up to 650 kg/ha from white clover (Trifolium repens L.). Despite a considerably lower input of 410 kg N/halyear in a treatment where return of dung and urine was simulated, it has been widely accepted in discussion of New Zealand agriculture (e.g., Levy 1970) that clovers in grazed pastures fix very large quantities of atmospheric N.…”

Section: Introductionmentioning

confidence: 99%

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XII. General discussion

Höglund

Crush

Brock

et al. 1979

New Zealand Journal of Experimental Agriculture

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Nitrogen relationships are discussed for nine grazing-trial sites throughout New Zealand. Measured clover growth and N fixation were not necessarily closely related, giving substantial seasonal and annual variation in N fixation per unit clover grown. Other factors, Including weather and soil characteristics, influenced the extent to which clovers obtained their nitrogen requirements from fixation or by direct uptake of soil N.Annual N fixation in developed lowland pastures was around 184 kg N/ha -less than half the value previously thought to occur. This lower value was consistent with lower clover yields and higher soil N status than recorded in earlier studies. Annual N turnover in the pastures was large, but showed no simple relationships with either N fixation or soil characteristics. Grass yields were relatively insensitive to climatic variation and not simply related to either clover yields or N fixation.

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Section: Discussionsupporting

confidence: 73%

Section: Discussionsupporting

confidence: 66%

Section: Soilsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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XII. General discussion

Höglund

Crush

Brock

et al. 1979

New Zealand Journal of Experimental Agriculture

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“…Table 4 presents the mean annual N gain in the system (herbage + soil), and although it is not a true value for actual N fixation (as losses from leaching, etc., are not accounted for), it will be referred to as N fixation for the purposes of this paper. "Background" N was not measured, but would probably have been similar to the 15 kg(ha estimated by Sears et al (1965). All legumes fixed more N at HP than at LP, white clover and lotus fixing twice as much as suckling clover.…”

Section: Changes In Total Soil Nitrogenmentioning

confidence: 99%

Growth and nitrogen fixation of pure stands of three pasture legumes with high/low phosphate

Brock¹

1973

New Zealand Journal of Agricultural Research

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ThJ ~rowth and N-fixation capacities of pure stands of white clover (Trifolium repens L), suckling clover (T. dubium Sibth.), and Lotus pedunculatus Cav. were compared under high and low phosphate conditions in mown plots for 3 years.With high inputs of P, white clover yielded 10% more herbage DM and nitrogen than lotus, but with low P input lotus yielded 30% more than white clover. The main factor operating was the greater ability of lotus to take up P from the soil. Full development of an efficient N-fixing system took a year in lotus, much longer than for white clover. Suckling clover performed better than white clover at low P during its growing season.White clover and lotus accumulated twice as much soil N as suckling clover. Phosphate had no effect on soil N accumulation.The mean annual amount of N fixed (herbage + soil) at high P was 570, 590, and 265 kg/ha, and at low P was 400, 410, and 195 kg/ha for white clover, lotus, and suckling cI over respectively.

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