scholarly journals Effects of long-term differences in fertiliser history on hill country: seasonal pasture production, legume growth and soil phosphorus status

1995 ◽  
pp. 105-109
Author(s):  
C.G. Roach ◽  
E.K.K. Nemaia ◽  
S.F. Ledgard ◽  
G.J. Brier ◽  
C.D.A. Mclay
Keyword(s):  
Soil Phosphorus ◽  
N Fixation ◽  
Pasture Production ◽  
P Deficiency ◽  
Soil P ◽  
Hill Country ◽  
Legume Production ◽  
Soil Measurements ◽  
Steep Slopes ◽  
Legume Growth

The effects of 10 years of nil or maintenance phosphorus (P) fertiliser (250 kg/ha/yr superphosphate) on pasture production and composition, and on soil P status, were measured in a farmlet trial on hill country near Te Kuiti. Withholding P resulted in 29-35% less annual pasture production and 54-72% less legume (predominantly white clover) production. There was little difference in seasonality of production between the two farmlets. The loss in production in the nil P farmlet was predictable based on the decline in soil Olsen P test to 6-8 ppm and the results from past mowing trials. Additional soil measurements revealed that soil organic P levels were increasing at the site and this will have contributed to the decline in plantavailable P in soil. Re-application of P at 23 kg/ha markedly increased legume growth (by 180-330%) in the nil P farmlet, which was proportionally twice as high on steep slopes as on easy slopes. This response in legume production was most evident in summer at a time when improved feed quality is valuable for finishing lambs. Indeed, legume growth in the P re-application plots exceeded that in the maintenance P farmlet by 23-28%. This reflected reduced plant-available soil N status due to less inputs from N, fixation in the previous 10 years, and thereby increased the competitive advantage of legumes over grasses where P deficiency was diminished by fertiliser re-application. Keywords: fertiliser history, hill country, legume production, pasture production, phosphorus, seasonality, soil phosphorus

scholarly journals Pasture responses to phosphorus and nitrogen fertilisers on dry hill country

1998 ◽  
pp. 135-140 ◽  
Author(s):  
A.G. Gillingham ◽  
M.H. Gray ◽  
D.R. Smith
Keyword(s):  
Soil Moisture ◽  
Large Scale ◽  
Slope Aspect ◽  
Nitrogen Response ◽  
Pasture Production ◽  
Soil P ◽  
Hill Country ◽  
Large Scale Field ◽  
The Difference ◽  
Steep Slopes

In order to evaluate the relative responsiveness of summer-dry hill pasture to phosphate (P) and nitrogen (N) fertilisers, a large scale field trial was established in southern Hawke's Bay in 1995. Pasture growth rates and species, and soil moisture levels were measured on easy and steep slopes of generally north- and south-facing aspects in two pairs of farmlets with either a Low or High soil P status, one of each pair also receiving 30 kg N/ha annually in winter. Soil moisture levels were always higher on south- than on north-facing slopes, the difference being greatest from autumn to spring. However, total annual pasture growth was higher on north aspects because of better winter production, whereas the colder, south aspects produced little pasture at this time. In other seasons, pasture growth was similar on both aspects. Pasture growth was higher on easy than on steep slopes at all times. P responses occurred from spring to autumn especially on south aspects, and on easy north-facing slopes, which showed a large increase in clover growth. N responses were best in winter and autumn especially on steep, north aspects and at Low P conditions. N application depressed clover production, especially in the High P+N fertiliser treatment, where there was no net increase in production compared with the High P treatment. Only tentative conclusions can be made at this time since the pasture is considered to be still in a development phase. However, results suggest that application of P only to south aspects and moist north slopes, and for steep, north-facing slopes to receive N, plus only limited P, will be the most efficient fertiliser policy. Keywords: dry hill country, phosphate response, nitrogen response, pasture production, slope, aspect

scholarly journals Roles of Phosphate Solubilizing Microorganisms from Managing Soil Phosphorus Deficiency to Mediating Biogeochemical P Cycle

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 158
Author(s):  
Jiang Tian ◽  
Fei Ge ◽  
Dayi Zhang ◽  
Songqiang Deng ◽  
Xingwang Liu
Keyword(s):  
Phosphorus Deficiency ◽  
Soil Phosphorus ◽  
Biological Molecules ◽  
P Deficiency ◽  
Soil P ◽  
Soil Systems ◽  
Intensively Managed ◽  
Phosphate Solubilizing ◽  
P Fertilizers ◽  
P Cycle

Phosphorus (P) is a vital element in biological molecules, and one of the main limiting elements for biomass production as plant-available P represents only a small fraction of total soil P. Increasing global food demand and modern agricultural consumption of P fertilizers could lead to excessive inputs of inorganic P in intensively managed croplands, consequently rising P losses and ongoing eutrophication of surface waters. Despite phosphate solubilizing microorganisms (PSMs) are widely accepted as eco-friendly P fertilizers for increasing agricultural productivity, a comprehensive and deeper understanding of the role of PSMs in P geochemical processes for managing P deficiency has received inadequate attention. In this review, we summarize the basic P forms and their geochemical and biological cycles in soil systems, how PSMs mediate soil P biogeochemical cycles, and the metabolic and enzymatic mechanisms behind these processes. We also highlight the important roles of PSMs in the biogeochemical P cycle and provide perspectives on several environmental issues to prioritize in future PSM applications.

Seasonal and fertilizer effects on the organic cycle and microbial biomass in a hill country soil under pasture

Soil Research ◽  
1992 ◽  
Vol 30 (3) ◽  
pp. 383 ◽  
Author(s):  
KW Perrott ◽  
SU Sarathchandra ◽  
BW Dow
Keyword(s):  
Microbial Biomass ◽  
Sodium Bicarbonate ◽  
Organic Phosphorus ◽  
Soil Phosphorus ◽  
Phosphorus Uptake ◽  
Phosphate Fertilizer ◽  
Inorganic Phosphorus ◽  
Pasture Production ◽  
Hill Country ◽  
Soil Microbial

A two year investigation of soil phosphorus and the soil organic cycle was carried out on a typical hill country site in the North Island, New Zealand. This included investigation of changes in soil phosphorus, as well as seasonal and fertilizer (superphosphate) effects on soil microbial phosphorus and sulfur, sodium bicarbonate extractable phosphorus and calcium chloride extractable sulfur. No net utilization of soil organic phosphorus occurred when application of phosphate fertilizer was withheld. On the contrary, accumulation of organic phosphorus was found in both fertilized and unfertilized plots. Immobilization of inorganic phosphorus into organic forms appeared to be a significant factor in fertilizer phosphorus requirements at this site. It was also a significant cause of the decline in the soil phosphorus status when no fertilizer was applied. Despite declining pasture production, there were no effects of withholding superphosphate on the soil biological cycle as measured by soil microbial phosphorus and sulfur, total organic phosphorus and sodium bicarbonate extractable organic phosphorus. However, seasonal variations occurred indicating storage and release of phosphorus by the soil organic matter and microbial biomass. Release of phosphorus occurred during periods of rapid pasture growth and could account for phosphorus uptake by the pasture at those times.

Response of Mediterranean grassland to phosphate and stocking rates: biomass production and botanical composition

1991 ◽  
Vol 116 (1) ◽  
pp. 37-46 ◽  
Author(s):  
A. E. Osman ◽  
P. S. Cocks ◽  
L. Russi ◽  
M. A. Pagnotta
Keyword(s):  
Seed Mass ◽  
Biomass Productivity ◽  
Ground Cover ◽  
Botanical Composition ◽  
Pasture Production ◽  
P Deficiency ◽  
Soil P ◽  
Legume Seeds ◽  
Native Grassland ◽  
Stocking Rates

SUMMARYThree rates of phosphate (0, 25, and 60 kg/ha P2O5) were applied to phosphorus-deficient native grassland at Tel Hadya, in northern Syria, and biomass productivity, botanical composition and number of legume seeds in the soil were monitored for five seasons (1984/85–1988/89). The experiment was grazed at low (0·8 sheep/ha per year) and high (1·7 sheep/ha per year) stocking rates from the second to the fourth seasons of the experiment; in the fifth season, the low and high stocking rates were increased to 1·1 and 2·3 sheep/ha per year, respectively. The experimental site was typical of native grassland within the cereal zone of west Asia, where cropping is not possible because of shallow, stony soils and steep slopes.The results showed that annual applications of phosphorus, even as low as 25 kg P2O5/ha, alleviated the deficiency in soil P and resulted in improved pasture production, even in dry years. Legume production showed the greatest response to P, increasing by 0·3–3 times the production of the control treatments. By the fifth season, legume seed mass had increased threefold and number of seeds sixfold in the P-treated plots, compared with the first season, while in the control plots there was little change. Rain-use efficiency on the P-treated plots was more than double that of the controls by the fourth and fifth seasons.Practical application of the results depends on whether (i) legumes are as frequent in native grasslands, as a whole, as they are at Tel Hadya, (ii) the P deficiency observed at Tel Hadya is widespread, and (iii) grazing of communally owned grasslands can be controlled. It is suggested that all three criteria will often be fulfilled and, therefore, that grassland productivity in west Asia could be substantially increased. Furthermore, the results suggest that above-ground cover and soil organic matter will also increase after P application, both of which will help to reduce soil erosion and thereby increase the sustainability of livestock production in west Asia.

Changes in soil phosphorus availability and potential phosphorus loss following cessation of phosphorus fertiliser inputs

Soil Research ◽  
2013 ◽  
Vol 51 (5) ◽  
pp. 427 ◽  
Author(s):  
R. J. Dodd ◽  
R. W. McDowell ◽  
L. M. Condron
Keyword(s):  
Agricultural Soils ◽  
Soil Phosphorus ◽  
Pasture Production ◽  
Soil P ◽  
Olsen P ◽  
P Loss ◽  
P Concentration ◽  
Rate Of Decline ◽  
P Retention

Long-term application of phosphorus (P) fertilisers to agricultural soils can lead to in the accumulation of P in soil. Determining the rate of decline in soil P following the cessation of P fertiliser inputs is critical to evaluating the potential for reducing P loss to surface waters. The aim of this study was to use isotope exchange kinetics to investigate the rate of decline in soil P pools and the distribution of P within these pools in grazed grassland soils following a halt to P fertiliser application. Soils were sourced from three long-term grassland trials in New Zealand, two of which were managed as sheep-grazed pasture and one where the grass was regularly cut and removed. There was no significant change in total soil P over the duration of each trial between any of the treatments, although there was a significant decrease in total inorganic P on two of the sites accompanied by an increase in the organic P pool, suggesting that over time P was becoming occluded within organic matter, reducing the plant availability. An equation was generated using the soil-P concentration exchangeable within 1 min (E1 min) and P retention of the soil to predict the time it would take for the water-extractable P (WEP) concentration to decline to a target value protective of water quality. This was compared with a similar equation generated in the previous study, which used the initial Olsen-P concentration and P retention as a predictor. The use of E1 min in place of Olsen-P did not greatly improve the fit of the model, and we suggest that the use of Olsen-P is sufficient to predict the rate of decline in WEP. Conversely, pasture production data, available for one of the trial sites, suggest that E1 min may be a better predictor of dry matter yield than Olsen-P.

scholarly journals Response to re-application of phosphate fertilisers on hill pasture where fertiliser had been withheld for seven years

1993 ◽  
pp. 67-71
Author(s):  
S.F. Ledgard ◽  
G.J. Brier
Keyword(s):  
Phosphate Rock ◽  
Nitrogen Availability ◽  
Research Area ◽  
N Fixation ◽  
Single Superphosphate ◽  
Pasture Production ◽  
Hill Country ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
P Rate

A field experiment at the AgResearch Te Kuiti Research Area examined effects of re-application of phosphorus (P) fertilisers on production and composition of hill pastures (1520% slope) which had received no P for 7 years. Treatments were 0, 20, 40 and 80 kg P/ha/year as single superphosphate (SSP) or North Carolina reactive phosphate rock (RPR). The soil was a yellowbrown earth/yellow-brown loam intergrade with Olsen P 9. Re-application of P produced a rapid and large increase in pasture production of up to 42 and 61% in years 1 and 2, respectively, and brought production up to 95% of that measured in neighbouring regularly fertilised paddocks. The pasture response to RPR was less (PcO.01) than that to SSP in both years, particularly at the highest rate. This indicated that RPR was less suitable for capital application. The P response was due almost entirely to an increase in white clover growth, and N, fixation was estimated to increase from 30 to 130 kg N/ha/year. In year 2, there was an increase in ryegrass content of pasture receiving the high P rate and this was attributed to increased nitrogen availability due to increased N, fixation. Keywords: hill country, phosphorus, reactive phosphate rock, superphosphate

scholarly journals SOIL FERTILITY AND HILL COUNTRY PRODUCTION

1982 ◽  
pp. 153-160 ◽  
Author(s):  
M.G. Lambert ◽  
P.C. Luscombe ◽  
D.A. Clark
Keyword(s):  
Summer Rainfall ◽  
Research Area ◽  
Grazing Management ◽  
Low Fertility ◽  
N Availability ◽  
Stocking Rate ◽  
Pasture Production ◽  
Hill Country ◽  
Olsen P ◽  
Legume Growth

Soil, pasture and animal responses to 2 levels of superphosphate were measured within a farmlet trial, at Ballantrae hill country research area, near Woodville, during 1975-80. Soil and pasture measurements were also made for 3 years before the trial started. Pastures, which were dominated by low-fertility-tolerant grasses (LFTC;), moss and flatweeds, were oversown with 4 legumes before the trial started. Soil Olsen P level was 5 under untopdressed pasture in 1973, and 9 in 1975 after application of 500 kg/ ha superphosphate. Superphosphate rates were 120 (on low fertiliser areas q LF) and 640 (on high fertiliser areas = HF) kg/ ha/ yr average during 1975/80. Annual pasture production (adjusted for variable summer rainfall) was 7.1 t DM/ ha from untopdressed pasture and 8.1 t following 500 kg superphosphate/ ha in 1973-74. LF production rose to 8.5, and HF to 12.0, in 1980. Legume contribution rose from 5% in untopdressed pasture to 18% and 23% in LF and HF respectively in 1975/76. By 1979/80 legume contribution had steadily declined to 10% on both treatments, probably due to a measured increase in soil N availability and increased competitiveness of associated grasses. Ryegrass content rose at both fertiliser levels, while LFTG content fell; these trends were greatest under HF. Winter stocking rate was increased from 6 to 10.9 and 14.9 su/ha on LF and HF-respectively. Per animal performance did not decrease. A range of techniques which could increase efficiency of superphosphate use in hill country is discussed. These techniques include: selective application to responsive pastures; spring application; grazing management to encourage legume growth.

scholarly journals Precise aerial fertiliser application on hill country

1999 ◽  
pp. 221-226
Author(s):  
A.G. Gillingham ◽  
J. Maber ◽  
J. Morton ◽  
M. Tuohy
Keyword(s):  
Application Rate ◽  
Economic Returns ◽  
Related Factors ◽  
Pasture Production ◽  
Economic Return ◽  
Soil P ◽  
Topographic Complexity ◽  
Hill Country ◽  
Olsen P ◽  
Fertiliser Application

The fertiliser requirements of hill country vary with soil type, slope and aspect-related factors which govern pasture production potential and species composition. In most situations, the topographic complexity is such that only very broad differentiation in land units can be made when aerially applying fertiliser. The traditional method of aerial topdressing is for superphosphate to be flown on at a common rate over large blocks of complex topography by fixed-wing aircraft. Advances in geographical positioning system (GPS) and aircraft technology now allow aircraft to fly accurately defined track spacing and so achieve optimum uniformity of fertiliser spread. The same technology could be used to vary fertiliser application rate along a flight path according to predetermined recommendations and through links to a farm geographic information system (GIS) map. This approach could also be used to apply different fertiliser types. In a desktop study the effects of differential, compared with uniform, fertiliser application policies, on animal productivity and economic returns were examined for three contrasting hill farm situations using a combination of trial results and the AgResearch PKS Lime Programme. Results showed that for a farm with a low soil P status (Olsen P =9), that stocking rate could be increased by 0.5 su/ha, and the economic return by 7.5%, by differential, rather than uniform fertiliser application. In a similar but higher soil P status farm (Olsen P = 15), the increase was 0.9 su/ ha and 10.1% respectively. In a summer-dry situation where nitrogen fertiliser could be substituted for some P fertiliser, a differential policy designed to optimise production gave a 2.1 su/ha and 43% net margin increase, compared with the uniform application of a typical rate of maintenance P fertiliser only. The results from the desktop study are discussed in relation to the practical aspects of developing differential fertiliser application methods. This will relate to extra fertiliser application cost, and the definition of practical sized land units and fertiliser forms, which will all have some effect on the net economics of a differential application policy. Despite these unknowns, the technology would appear to offer real gains to the hill country farmer. Keywords: economic return, fertiliser application, GIS, GPS, hill country, phosphate

Long term effects of withholding phosphate application on North Island hill country: Economics

1990 ◽  
pp. 29-33
Author(s):  
D.A. Clark ◽  
S.F. Ledgard ◽  
M.G. Lambert ◽  
M.B. O'Connor ◽  
A.G. Gillingham
Keyword(s):  
Cash Flows ◽  
Cost Ratio ◽  
Long Term Effects ◽  
Pasture Production ◽  
Soil P ◽  
Hill Country ◽  
Fertiliser Application ◽  
Positive Cash Flow ◽  
Sustainable Productivity

Results from fertiliser cessation experiments at Ballantrae, Te Kuiti and Whatawhata, on yellow-brown earths, were used to evaluate the fertiliser cessation compared to continued application on hill country breeding ewe systems. At Balhmtrae, on farmlets previously receiving 125 kg superphosphate/ha/yr, continued fertiliser application generated a positive cash flow after 8 years. On farmIets previously receiving rates of 200-375 kg superphosphate/ha/yr positive cash flows were generated by continued fertiliser application after 4, 5 and 6 years at Te Kuiti, Whatawhata and Ballantrae respectively. Fertiliser cessation is a sound strategy to survive periods of low product price:fertiIiser cost ratio. However, it will decrease sustainable productivity and hence farm resale value. Fertiliser recommendations cannot remain constant over time but must consider: animal enterprise, product and fertiliser price, soil P status, and level of pasture utilisation. Keywords fertiliser cessation, superphosphate, Olsen P, economics, hill country, pasture production

scholarly journals High Soil Phosphorus Application Significantly Increased Grain Yield, Phosphorus Content but Not Zinc Content of Cowpea Grains

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 802
Author(s):  
Saba B. Mohammed ◽  
Daniel K. Dzidzienyo ◽  
Adama Yahaya ◽  
Muhammad L. Umar ◽  
Muhammad F. Ishiyaku ◽  
...  
Keyword(s):  
Grain Yield ◽  
Soil Phosphorus ◽  
P Deficiency ◽  
Soil P ◽  
High Soil ◽  
Wide Range ◽  
Zn Content ◽  
P Application ◽  
Phosphorus Application ◽  
The Impact

To ameliorate the impact of soil phosphorus (P) deficiency on cowpea, the use of P-based fertilizers is recommended. Plant zinc (Zn) is an essential nutrient required by plants in a wide range of processes, such as growth hormone production and metabolism. However, a negative association between plant Zn content and high P application has been reported in some crops. There are few reports about soil P application and plant Zn content relationship on cowpea. Thus, this study investigated the response of cowpeas to three P rates in the screenhouse (0, 1.5, and 30 mg P/kg) and field (0, 10, and 60 kg P2O5/ha) and their effects on plant P and Zn content, biomass, and grain yield. In the screenhouse, shoot and root dry weights, and shoot P and Zn content were measured. Shoot dry weight, grain yield, grain P, and Zn contents were determined from field plants. Higher rates of P led to increased shoot biomass and grain yield of the field experiment but were not associated with a significant change in shoot or grain Zn content. There was not a significant correlation between grain yield and Zn content in high soil P (p < 0.05). The effect of higher P application on reduced plant Zn contents may be genotype-dependent and could be circumvented if genotypes with high Zn content under high soil P are identified.

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