Proceedings of the New Zealand Grassland Association, 1984
Three fertiliser trials on hill country yellow-brown earths are discussed, The results show that ... more Three fertiliser trials on hill country yellow-brown earths are discussed, The results show that on a newly sown ryegrass (Lolium perenne) white clover (Trifolium repens) Pasture 90% maximum pasture production was achieved at an Olsen P level of 13-15 ppm. On a reverted browntop (Agrostis tenuis) pasture an Olsen P concentration of at least 25 ppm was required for 90% maximum production. Reasons for this difference are discussed. Liming increased pasture dry matter production on all sites and the largest increases in production occurred at low (1.25 t/ha) rates. There was no evidence that liming enhanced P availability and therefore lime and P requirements for these soils should be considered independently. Phosphorus applications generally increased legume production but the effects of lime were variable. On the Mahoenui soil liming increased grass growth at the expense of the legume component but on the Marua soils liming increased the legume content. An explanation for this is su...
In the last decade major reviews on the phosphorus (P), potassium (K) and sulphur (S) nutrient re... more In the last decade major reviews on the phosphorus (P), potassium (K) and sulphur (S) nutrient requirements of clover-based pastures in New Zealand have been completed. This has resulted in adjustments to the P, K and S pasture production functions and some changes to the critical levels for soil tests, and modifications to our interpretation of some soil tests such as Organic S and Reserve K. Applying this new information to New Zealand's hill country pastoral soils, using case studies, suggests that there is considerable unrealized potential to increase productivity. Keywords: critical levels, economics, fertiliser, pasture, phosphorus, potassium, soil fertility, soil tests, sulphur
Proceedings of the New Zealand Grassland Association, 1990
A field trial was conducted on a yellow-grey earth in the Hawke's Bay (mean annual rainfall 8... more A field trial was conducted on a yellow-grey earth in the Hawke's Bay (mean annual rainfall 875 mm) over a period of 5 years to measure the effects of lime applications (0, 5, 10 t/ha) on soils high (50 kg P/ha applied annually) or low (5 kg P/ha applied annually) in phosphorus (P). The average annual pasture production on this dryland soil in the absence of applied lime or P was 5060 kg DM/ha (range 3861-6024). The botanical composition of the pasture was variable, average annual legume composition (4/o on DM basis) ranging from 3 to 42%. The predominant. legume was subterranean clover (Trifolium subterranean) with white clover (Trifolium repens) making a small contribution in some years. In the first two years after application responses to lime were large (lo-20%), due entirely to liming stimulating the grass component of the pasture, and consistent with liming enhancing the rate of net mineralisation of soil organic nitrogen (N). In years three and-four-the-dominant treatmen...
Australian Journal of Experimental Agriculture, 2005
This review consolidates and updates our understanding of the diagnosis and correction of soil S ... more This review consolidates and updates our understanding of the diagnosis and correction of soil S deficiencies, and the management of S requirements for pastures, using both historical data from field trials and recent developments in the understanding of the sulfur (S) cycle in New Zealand pastoral soils. The basis for, and the practical implications of, a new quasi-equilibrium S model for pastures is discussed in terms of the size and changes in the pools of sulfate S, readily available extractable organic S (EOS) and total organic S over time and with the addition and removal of S through fertiliser and leaching. With this background, the use and interpretation of the 2 S soil tests are discussed. Historical data from field trials and the recent research on nutrient ratios are used to update the use of pasture S concentrations for diagnosing S deficiency. Historical data is also used to examine the distribution and size of pasture responses to S fertiliser and to define the biolog...
New Zealand Journal of Agricultural Research, 1997
The amount of plant nitrogen (N) uptake from the soil and fixed N in the herbage of clover specie... more The amount of plant nitrogen (N) uptake from the soil and fixed N in the herbage of clover species were measured using a N dilution technique on mowing trials at 3 lime rates (0, 5000, and 10 000 kg/ha) at a low rainfall site (Matapiro soil) near Hastings over 5 years and at a high rainfall site (Mangatea soil) near
A field trial was conducted on a yellow-grey earth in the Hawke’s Bay (mean annual rainfall 875 m... more A field trial was conducted on a yellow-grey earth in the Hawke’s Bay (mean annual rainfall 875 mm) over a period of 5 years to measure the effects of lime applications (0, 5, 10 t/ha) on soils high (50 kg P/ha applied annually) or low (5 kg P/ha applied annually) in phosphorus (P). The average annual pasture production on this dryland soil in the absence of applied lime or P was 5060 kg DM/ha (range 3861-6024). The botanical composition of the pasture was variable, average annual legume composition (4/o on DM basis) ranging from 3 to 42%. The predominant. legume was subterranean clover (Trifolium subterranean) with white clover (Trifolium repens) making a small contribution in some years. In the first two years after application responses to lime were large (lo-20%), due entirely to liming stimulating the grass component of the pasture, and consistent with liming enhancing the rate of net mineralisation of soil organic nitrogen (N). In years three and-four-the-dominant treatment ef...
Proceedings of the New Zealand Grassland Association, 1984
Three fertiliser trials on hill country yellow-brown earths are discussed, The results show that ... more Three fertiliser trials on hill country yellow-brown earths are discussed, The results show that on a newly sown ryegrass (Lolium perenne) white clover (Trifolium repens) Pasture 90% maximum pasture production was achieved at an Olsen P level of 13-15 ppm. On a reverted browntop (Agrostis tenuis) pasture an Olsen P concentration of at least 25 ppm was required for 90% maximum production. Reasons for this difference are discussed. Liming increased pasture dry matter production on all sites and the largest increases in production occurred at low (1.25 t/ha) rates. There was no evidence that liming enhanced P availability and therefore lime and P requirements for these soils should be considered independently. Phosphorus applications generally increased legume production but the effects of lime were variable. On the Mahoenui soil liming increased grass growth at the expense of the legume component but on the Marua soils liming increased the legume content. An explanation for this is su...
In the last decade major reviews on the phosphorus (P), potassium (K) and sulphur (S) nutrient re... more In the last decade major reviews on the phosphorus (P), potassium (K) and sulphur (S) nutrient requirements of clover-based pastures in New Zealand have been completed. This has resulted in adjustments to the P, K and S pasture production functions and some changes to the critical levels for soil tests, and modifications to our interpretation of some soil tests such as Organic S and Reserve K. Applying this new information to New Zealand's hill country pastoral soils, using case studies, suggests that there is considerable unrealized potential to increase productivity. Keywords: critical levels, economics, fertiliser, pasture, phosphorus, potassium, soil fertility, soil tests, sulphur
Proceedings of the New Zealand Grassland Association, 1990
A field trial was conducted on a yellow-grey earth in the Hawke's Bay (mean annual rainfall 8... more A field trial was conducted on a yellow-grey earth in the Hawke's Bay (mean annual rainfall 875 mm) over a period of 5 years to measure the effects of lime applications (0, 5, 10 t/ha) on soils high (50 kg P/ha applied annually) or low (5 kg P/ha applied annually) in phosphorus (P). The average annual pasture production on this dryland soil in the absence of applied lime or P was 5060 kg DM/ha (range 3861-6024). The botanical composition of the pasture was variable, average annual legume composition (4/o on DM basis) ranging from 3 to 42%. The predominant. legume was subterranean clover (Trifolium subterranean) with white clover (Trifolium repens) making a small contribution in some years. In the first two years after application responses to lime were large (lo-20%), due entirely to liming stimulating the grass component of the pasture, and consistent with liming enhancing the rate of net mineralisation of soil organic nitrogen (N). In years three and-four-the-dominant treatmen...
Australian Journal of Experimental Agriculture, 2005
This review consolidates and updates our understanding of the diagnosis and correction of soil S ... more This review consolidates and updates our understanding of the diagnosis and correction of soil S deficiencies, and the management of S requirements for pastures, using both historical data from field trials and recent developments in the understanding of the sulfur (S) cycle in New Zealand pastoral soils. The basis for, and the practical implications of, a new quasi-equilibrium S model for pastures is discussed in terms of the size and changes in the pools of sulfate S, readily available extractable organic S (EOS) and total organic S over time and with the addition and removal of S through fertiliser and leaching. With this background, the use and interpretation of the 2 S soil tests are discussed. Historical data from field trials and the recent research on nutrient ratios are used to update the use of pasture S concentrations for diagnosing S deficiency. Historical data is also used to examine the distribution and size of pasture responses to S fertiliser and to define the biolog...
New Zealand Journal of Agricultural Research, 1997
The amount of plant nitrogen (N) uptake from the soil and fixed N in the herbage of clover specie... more The amount of plant nitrogen (N) uptake from the soil and fixed N in the herbage of clover species were measured using a N dilution technique on mowing trials at 3 lime rates (0, 5000, and 10 000 kg/ha) at a low rainfall site (Matapiro soil) near Hastings over 5 years and at a high rainfall site (Mangatea soil) near
A field trial was conducted on a yellow-grey earth in the Hawke’s Bay (mean annual rainfall 875 m... more A field trial was conducted on a yellow-grey earth in the Hawke’s Bay (mean annual rainfall 875 mm) over a period of 5 years to measure the effects of lime applications (0, 5, 10 t/ha) on soils high (50 kg P/ha applied annually) or low (5 kg P/ha applied annually) in phosphorus (P). The average annual pasture production on this dryland soil in the absence of applied lime or P was 5060 kg DM/ha (range 3861-6024). The botanical composition of the pasture was variable, average annual legume composition (4/o on DM basis) ranging from 3 to 42%. The predominant. legume was subterranean clover (Trifolium subterranean) with white clover (Trifolium repens) making a small contribution in some years. In the first two years after application responses to lime were large (lo-20%), due entirely to liming stimulating the grass component of the pasture, and consistent with liming enhancing the rate of net mineralisation of soil organic nitrogen (N). In years three and-four-the-dominant treatment ef...
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