Effects of nitrogen, phosphorus and potassium application rates on the botanical composition of an irrigated sward

1993 ◽  
pp. 381-390
Author(s):  
M. O. Torres ◽  
F. Calouro ◽  
A. Barata
Keyword(s):  
Botanical Composition ◽  
Application Rates ◽  
Potassium Application ◽  
Phosphorus And Potassium ◽  
Nitrogen Phosphorus

Effect of nitrogen, phosphorus and potassium application on yield of potato tubers (Solatium tuberosum L.)

1987 ◽  
Vol 108 (2) ◽  
pp. 321-329 ◽  
Author(s):  
U. C. Sharma ◽  
B. R. Arora
Keyword(s):  
Field Experiments ◽  
Sandy Loam ◽  
Farmyard Manure ◽  
Potato Tubers ◽  
Solatium Tuberosum ◽  
Loam Soil ◽  
Potassium Application ◽  
Phosphorus And Potassium ◽  
Grade Increase ◽  
Nitrogen Phosphorus

SummarySix field experiments, three each during 1982–3 and 1983–4, were conducted on a sandy loam soil to study the effect of varying levels of nitrogen, phosphorus and potassium, in the absence and presence of farmyard manure (FYM) (30 t/ha), on the number of tubers and yield of potato in three grades. Increase in nitrogen, phosphorus and potassium application, in the absence or presence of FYM, did not significantly affect the total number of tubers/m2 but did affect the number of tubers in different grades. An increase in nitrogen and potassium significantly decreased the number of tubers/m2 in small (< 25 g) and increased in medium (25–75 g) and large (> 75 g) grades at 45, 60, 75 and 90 days after planting. Increase in the application of phosphorus increased the number of tubers/m2 in the small grade and decreased it in the large grade but did not affect the number in the medium grade. Increase in nitrogen and potassium application decreased the tuber yield in the small grade and increased it in the medium and large grades. Applied phosphorus increased the yield in the small and medium grades and decreased it in the large grade. The increase in the yield of tubers with increase in nitrogen and potassium application was found to be caused by an increase in the number of tubers in the medium and large grades at the expense of the small grade; however, with applied phosphorus the increase in yield was due to increase in the weight of individual tubers within the small and medium grades. FYM application decreased the number of tubers in the small grade and increased it in the medium and large grades. The response of potato to nitrogen increased and to phosphorus and potassium decreased with the application of FYM.

Some long-term effects of slurry on grassland

1987 ◽  
Vol 108 (3) ◽  
pp. 529-541 ◽  
Author(s):  
P. Christie
Keyword(s):  
Application Rate ◽  
Nutrient Concentrations ◽  
Soluble Nitrogen ◽  
Pig Slurry ◽  
Botanical Composition ◽  
Long Term Effects ◽  
Application Rates ◽  
Herbage Yield ◽  
Phosphorus And Potassium ◽  
Cow Slurry

SummaryA field experiment is described in which three rates of pig and cow slurry were applied to a ryegrass sward over a period of 16 years. The experiment included control plots and plots receiving fertilizer supplying 200 kg N, 32 kg P and 160 kg K/ha per year.The slurry nutrient concentrations were similar to published values. Pig slurry was more variable than cow slurry and both varied significantly from year to year. Slurry was applied at 50, 100 or 200 m3/ha per year, with each rate divided into three equal applications.Even the highest slurry application rate did not depress herbage yield, which showed a typical response curve to the amount of soluble nitrogen applied. The ammoniumnitrogen content of slurry (61% on average) gave an adequate measure of its effect on herbage yield when it was applied three times per year in spring and summer.Recovery of phosphorus in the herbage averaged 30% from pig slurry, 40% from cow slurry and 66% from-fertilizer. Pig slurry supplied more phosphorus than did cow slurry, and herbage phosphorus content was significantly correlated with the amount applied. Much of the slurry phosphorus may have been organically bound and not available to plants in the short term.Recovery of potassium from pig slurry and fertilizer was nearly 90% and from cow slurry about 70%. Cow slurry supplied potassium in excess of crop requirements so that it accumulated in the soil under the largest dressing. Soil phosphorus reserves declined under the smallest dressing of cow slurry but were maintained at higher application rates. The pig slurry produced a marked accumulation of phosphorus under the largest dressing. The substantial accumulations of phosphorus and potassium from pig and cow slurry respectively gave marked penetration of the soil below 10 cm depth only at the highest application rate. The data suggest that at rates typical of farm practice significant losses of phosphorus and potassium from the rooting zone would be unlikely to occur.The main invading plant species were Agrostis stolonifera L. and Poa spp. Small slurry dressings produced a similar botanical composition to that of plots given fertilizer. Increasing slurry application rates decreased the proportion of L. perenne and increased that of A. stolonifera but only under the largest dressing did L. perenne fall to a small proportion of the sward and A. stolonifera become very dominant. L. perenne made maximum contribution to herbage dry-matter yield early in the season while the proportion of A. stolonifera increased as the season progressed.Under these conditions even extremely large slurry dressings did not depress herbage yield and may not necessarily have reduced herbage quality despite marked changes in sward botanical composition.

The effcts of fertilizers on herbage production. II. The effect of nitrogen, phosphorus and potassium on botanical and chemical composition

1964 ◽  
Vol 63 (2) ◽  
pp. 209-219 ◽  
Author(s):  
J. W. S. Reith ◽  
R. H. E. Inkson ◽  
W. Holmes ◽  
D. S. Maclusky ◽  
D. Reid ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Botanical Composition ◽  
Factorial Experiments ◽  
Rye Grass ◽  
N Treatment ◽  
Phosphorus And Potassium ◽  
Nitrogen Phosphorus ◽  
Clover Content

Six factorial experiments, each lasting 3 years, were carried out to determine the effects of N, P and K on herbage cut five times each year.Clover almost disappeared with the 87 lb. N treatment and none survived with the 174and 348 lb. dressings. N increased the proportions of rye-grass and cocksfoot in the sward. P had no influence on botanical composition. K usually increased the clover content in the absence of, but had practically no effect in the presence of, N.

EFFECTS OF LONG-TERM SURFACE APPLICATIONS OF LIMESTONE AND FERTILIZERS TO PERMANENT HAYLAND

1960 ◽  
Vol 40 (1) ◽  
pp. 28-34 ◽  
Author(s):  
L. B. MacLeod ◽  
R. F. Bishop ◽  
L. P. Jackson ◽  
E. T. Goring
Keyword(s):  
Phosphorus Content ◽  
Soil Phosphorus ◽  
Chemical Properties ◽  
Yield Response ◽  
Botanical Composition ◽  
Phosphorus And Potassium ◽  
Nitrogen Phosphorus

Limestone, nitrogen, phosphorus and potassium, alone and in various combinations, were applied to the surface of permanent hayland during a 27-year period. Both limestone and phosphorus produced marked changes in the chemical properties of the soil. Phosphorus content of the soil where surface applications of this fertilizer were made decreased markedly with depth of sampling. Yield response to phosphorus was greater than to nitrogen or potassium although changes in botanical composition of the sward indicated the value of nitrogen, for grass and of limestone for legumes. Irrespective of the treatment, yields declined with time.

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