Plant nutrition studies on some yellow and red earth soils in northern Cape York Peninsula. 2. Phosphorus: plant response and soil retention

1976 ◽  
Vol 16 (81) ◽  
pp. 542 ◽  
Author(s):  
WH Winter ◽  
GP Gillman

The response of a Stylosanthes guyanensislBrachiaria decumbens pasture to phosphorus on a yellow earth soil in northern Cape York Peninsula was studied over three years. Establishment rates of 0 to 130 kg ha-1 P were used followed by various combinations of 0 or 20 kg ha-1 P in the next two years. With comparisons made at the same cumulative P rate the dry matter and nitrogen yields were not affected by timing of application but P yield was increased in the third year when P was freshly applied. The dry matter yield response was modified by the botanical composition of the pasture. In the first year the pasture was 90-95 per cent legume and 110 kg ha-1 P was required to give 90 per cent of the presumed maximum yield whereas in the third year when the legume content was lower, (increasing from 10 to 40 per cent with P rate) this requirement had been reduced to about 90 kg ha-1 P. The third year P yield data were used to show that the value of applied P declined by about 70 per cent each year. After three years all the applied P was recovered in the 0-60 cm zone and the distribution was not affected by timing of application. In the 0-10 cm zone the acid extractable P increased from 0 with no P applied to 40 p.p.m. with 150 kg ha-1 P applied.


1989 ◽  
Vol 25 (4) ◽  
pp. 447-460 ◽  
Author(s):  
R. A. Date ◽  
D. Ratcliff

SUMMARYNodulated plants of Stylosanthes hamata, S. guianensis, S. humilis, S. scabra and S. fruticosa were grown in controlled environments with varied root and shoot temperatures. Measurement of dry matter and nitrogen content suggested that shoot temperature may be more important than root temperature in controlling growth and nitrogen fixation. There were strong interactions with variety. A fall in relative growth rate with increase in shoot temperature was least for S. guianensis and greatest for S. hamata and S. scabra. The optimum root temperature for growth and nitrogen fixation was approximately 30°C. Ninety percent maximum yield was achieved between root temperatures of 15–36°C for growth and 23–34°C for nitrogen fixation but varied with variety. Nitrogen fixation was more sensitive than dry weight to root temperature. The pattern of response of percentage nitrogen and nitrogen fixation efficiency reflected those for dry weight and nitrogen yields. Shoot to root ratios decreased toward the optimum root temperature then increased at the highest temperature. The reaction of varieties to root and shoot temperatures may be an important factor in determining their suitability for new regions.



1965 ◽  
Vol 5 (17) ◽  
pp. 120 ◽  
Author(s):  
MJT Norman

In an experiment at Katherine, N.T., the response of birdwood grass-Townsville lucerne (Cenchrus setigerus Vahl and Stylosanthes hurnilis H.B.K.) pasture sown on virgin land to levels of superphosphate and Christmas Island rock phosphate dust and to levels of superphosphate subsequently applied annually for three years was measured. There were no significant interactions between initial and annual applications. Initial applications of 2 and 4 cwt an acre superphosphate both gave higher forage yields of dry matter and nitrogen than 2 and 4 cwt an acre rock phosphate over the experimental period. Phosphorus yield of forage was a function of rate rather than of type of fertilizer. Annual superphosphate applications up to 1 cwt an acre increased the dry matter and nitrogen yields of the grass, but not those of the legume, and increased the phosphorus yield of both. The higher proportion of grass at high superphosphate levels was interpreted as a difference in responsiveness of the two species. A regime of 2 cwt an acre superphosphate initially and 1/2 cwt an acre annually produced 90 per cent of what was considered to be the maximum yield.



1967 ◽  
Vol 69 (3) ◽  
pp. 391-397 ◽  
Author(s):  
B. F. Bland

1. Dry-matter and nitrogen yields were recorded from perennial ryegrass-white clover associations which were defoliated 2, 4 or 6 times a year during the period 1963 to 1965.2. The average yearly output of dry matter was approximately 4000, 7000 and 6000 lb/acre for 1963, 1964 and 1965 respectively. Nitrogen harvested amounted to 132, 184 and 179 lb N/acre.3. The mean annual dry-matter yields from 2, 4 and 6 defoliations were 5300, 6100 and 6000 lb/acre and the corresponding figures for nitrogen yields were 112, 166 and 217 lb N/acre.4. Both segregation of the species below ground and increasing the defoliation frequency were responsible for higher contributions towards drymatter and nitrogen yield from the clover component.5. A comparison of the nitrogen yields between the plots with species segregated rather than integrated below ground suggests that the effects of underground nitrogen transference from 30–31 lb N/acre could first be demonstrated in the spring of the third year.



1985 ◽  
Vol 105 (2) ◽  
pp. 381-387 ◽  
Author(s):  
D. Reid

SUMMARYThe yield results are reported for an experiment in which 21 rates of nitrogen fertilizer were applied on pure-sown swards of four grasses, S. 24 and Barvestra perennial ryegrass, S. 37 cocksfoot and S. 53 meadow fescue. Growth curves fitted to the herbage yield data for each grass in each year are presented. On average the total dry-matter yield curves for the two ryegrasses were similar to one another, but showed a slightly smaller response to nitrogen rates below 300 kg/ha than did S. 23 ryegrass in an earlier experiment, and a more rapid decrease in response at higher rates. S. 37 cocksfoot had a similar dry-matter yield response to the ryegrasses at the low nitrogen rates, but the response decreased more rapidly at nitrogen rates over 250 kg/ha. The dry-matter yield response of S. 53 fescue decreased even more rapidly with nitrogen rates over 200 kg/ha. The mean estimates of the optimal nitrogen rate for each of the four grasses, i.e. the nitrogen rate at which the dry-matter response had decreased to 10 kg/kg N, was 380, 372, 357 and 327 kg N/ha for S. 24, Barvestra, S. 37 and S. 53 respectively, compared with 409 kg/ha for S. 23 ryegrass in the earlier experiment.



2020 ◽  
pp. 20-24
Author(s):  
Anna Nikolaevna Kshnikatkina ◽  
Elena Aleksandrovna Zueva ◽  
Inna Aleksandrovna Voronova ◽  
Anna Anatolyevna Belyaeva

In the course of studies, it was found that taking inoculation of Scarlet amaranth and Poterium polygama seeds with biologics has a positive effect on the formation of photosynthesis parameters. In amaranth agrocenoses during the panicle sweeping phase, the leaf surface area was significantly higher when seeds were inoculated with biological products than in the control variant for Kizlyarets cultivar by 23.1-36.3% and Valentina cultivar by 23.8-38.0%, the most effective the method was exogenous seed treatment with agric. The maximum parameters of photosynthesis were noted during seed maturation. So, on average for three years of research, the leaf area of the Kizlyarets variety was 64.1 and the Valentine variety 62.3 thousand m2 / ha, the photosynthetic potential, respectively, was 2.05 and 1.98 million m2 days / ha, the net productivity of photosynthesis - 8.56 and 7.66 g / m2 per day. The most intensive increase in the leaf area in the crops of the blackhead was noted in the budding phase, according to the experimental variants, it amounted to 40.8-45.3 thousand m2 / ha in the first year of use, and 41.9-46.8 thousand m2 in the second year of use / ha, in the third year of use - 42.8-47.4 thousand m2 / ha On average, over three years the largest collection of dry matter (6.9 t / ha), feed units (9.1 t / ha), digestible protein (1.45 t / ha) and metabolic energy (81.6 GJ) were obtained from Kizlyarets varieties when inoculating seeds with Agrika biological product. At the same time, the highest seed yield was obtained (1.31 t / ha), which is 2.39 times higher than the control variant and 1.44 times higher than the Valentina variety. Optimization of the plant’s mineral nutrition by seed inoculation with associative bacterial preparations provided for an increase in the productivity of the polygamous monofil. The yield of green mass of the Poterium polygama of the first year of use for an average of three years according to the experimental options was 28.5–31.8 t / ha, collection of dry matter – 7.3–8.2 t / ha, feed units – 4.36–4.87 t / ha, digestible protein - 0.56–0.65 t / ha, exchange energy - 88.7–99.6 GJ. The highest productivity of the blackhead was when treating seeds with Agrika with microelements together with Azotobacter: green mass - 31.8 t / ha, dry matter collection - 8.2 t / ha, feed units - 4.87 t / ha, digestible protein – 0.65 t / ha, exchange energy - 99.6 GJ, which significantly exceeds the performance of the control option. The treatment of seeds with biologics provided an increase in the seed productivity of the polygonidae by 91.7–223.1 kg / ha (10.1–24.6%). The highest seed yield in the first year of use is 1130.1 kg / ha, the second year of use is 1258.9 kg / ha, the third year of use is 1268.3 kg / ha, which significantly exceeds the control indicators by 27.3% and 27.8% was obtained during bacterization of seeds with Agrika, enriched with microelements and together with Azotobacter.



1982 ◽  
Vol 33 (4) ◽  
pp. 705 ◽  
Author(s):  
BA Rowe

A simple relation between the annual wool production per animal (y) and the amount of pasture dry matter produced per animal (x) was derived and tested using the results from a grazing experiment in which the effects of superphosphate and stocking rate on wool and pasture dry matter production were measured from pastures which were continuously grazed by Merino wethers for 3 years. The linear relation, y = a + b/x, accounted for 63% of the variance in wool production per animal in the first year, 82 % in the second and 97 % in the third. Exclusion of an outlier from the first year results increased the variance accounted for to 85 %. This model is simpler and more precise than some others that have been published. It is also consistent with the curvilinear relation between production per animal (y) and pasture production per animal (x).



1993 ◽  
Vol 121 (2) ◽  
pp. 233-240 ◽  
Author(s):  
P. C. Garnsworthy ◽  
D. T. Stokes

SUMMARYThe production of biomass and its partitioning into stem, leaf, ear and dead material were monitored weekly in crops of wheat and oats from 16 May 1990, which corresponded approximately to ear emergence in the wheat, until ensilage on 29 June, 7 July and 19 July 1990 using the Ag-Bag system. An enzyme/inoculant additive was used on both crops on each ensilage date, although a portion of oats was ensiled without additive on the first two cutting dates, giving a total of eight silages. Changes in rumen degradability of dry matter were assessed for both crops throughout the monitoring period using the synthetic fibre bag technique. The digestibilities of gross energy, modified acid detergent fibre, organic matter and crude protein were determined in vivo using sheep.Over the total period of monitoring, the daily rates of increase in dry matter (DM) yield were 15·1 (± 1·6) and 16·5 (±1·9) g DM/m2 for wheat and oats respectively. From 29 June to 19 July the rates of increase were 11·3 (± 3·1) and 23·1 (±6·0) g DM/m2. The increase in weight of the ears accounted for almost all of this increase and, by the end of the monitoring period, the ears contributed approximately half of the dry matter of each crop. In both crops the portion of dead material was small until 19 July, when there was a rapid increase in the amount of dead stem. The DM content of both crops remained < 30% up to day 33 (18 June) but increased from c. 33% to c. 52% between days 53 and 65 (8–20 July). Rumen degradability of both crops decreased rapidly from c. 66% on 16 May until 16 June, when it was c. 56% for wheat and 55% for oats; it remained constant at these values thereafter.For silages made on the three successive ensilage dates, there was an increase in DM and starch contents but decreases in digestible energy, digestible fibre and digestible crude protein contents. Digestible organic matter was similar for the first two ensilage dates but lower in silage made on the third date.The use of an additive with the oat crop resulted in decreases in the digestible energy, digestible organic matter and digestible crude protein contents of the silages compared with untreated oats.Maximum yield of DM from wheat (18·6 t/ha) was obtained with the third cutting date, but optimum yield of energy (170 GJ/ha) and digestible crude protein (746 kg/ha) were found at the second cutting date. For oats, maximum yield of DM (17·3 t/ha) was again found with the third cut and maximum yield of energy (159 GJ/ha, untreated; 140 GJ/ha with additive) with the second cut. Digestible crude protein yield was greatest with the second cut of oats when no additive was used (708 kg/ha) but with additive it was greatest with the first cut (661 kg/ha).It was concluded that, under these conditions, the optimum date for ensilage of wheat or oats was 7 July and that the use of the additive was detrimental to the quality of the oat silage.



2001 ◽  
Vol 37 (3) ◽  
pp. 361-372 ◽  
Author(s):  
W. K. Ng'etich ◽  
W. Stephens ◽  
C. O. Othieno

In an experiment on genotype × environment interactions in tea (Camellia sinensis), yield differed between the genotypes at all sites. The highest yield in the third year after planting was 3760 kg ha−1 for clone S15/10 at site 4 (1800 m altitude), while the lowest was 1610 kg ha−1 for clone 6/8 at site 1 (2200 m). The dry matter contents of harvested shoots from each clone ranged from 0.24 for clone TN14-3 down to 0.19 for clone S15/10. Yield response to soil water deficits was more pronounced at site 4, where larger deficits were observed. Hail damage affected the yield of two sites and a temperature influence on recovery was evident.



1962 ◽  
Vol 2 (7) ◽  
pp. 221 ◽  
Author(s):  
MJT Norman

At Katherine, N.T., between 1959-60 and 1961-62, the performance of Townsville lucerne alone and of mixtures of Townsville lucerne with Gayndah buffel grass, Biloela buffel grass, birdwood grass, and Sorghum almum was compared at three frequencies of wet-season cutting. The two most satisfactory mixtures, Townsville lucerne with Gaynahh buffel and birdwood grass, differed little in performance. Over three years, their average dry matter production exceeded that of Townsville lucerne alone by 45 per cent, but average nitrogen production was not appreciably greater than that of the pure legume pasture. Biloela buffel grass is considered to be an unsuitable companion grass for Townsville lucerne because of its competitive power. After three years, the dry matter contribution of the legume in Biloela buffel mixtures was only 18 per cent under the most favourable cutting treatment. The Sorghum almum mixture gave the highest dry matter yield in the first year, but the grass did not survive well, and by the third year the pasture was mainly Townsville lucerne. Sorghum almum may be useful in providing bulk in the early years of an intended pure legume pasture. The role of a perennial grass component in Townsville lucerne pastures is discussed.



1981 ◽  
Vol 32 (5) ◽  
pp. 703 ◽  
Author(s):  
I Papastylianou ◽  
DW Puckridge ◽  
ED Carter

The residual effects of one season of five cultural treatments common in southern Australian dryland farming were examined with respect to soil water and nitrogen, and the production of cereals in the next two years. The initial treatments were medic or subterranean clover pasture, faba beans, oats or bare fallow. In the second year barley, wheat and triticale were grown on the same plots, with 0,30,60 or 90 kg ha-1 of fertilizer nitrogen. Wheat was sown over the whole area for the third season. The medic and subterranean clover pastures contributed approximately 100 kg ha-1 of nitrogen in top growth, but this remained on the surface until cultivation. Oats and fallow plots declined in total soil nitrogen by about 70 kg ha-1. The nitrogen content of the faba bean stubble showed that this crop has the potential of providing equivalent nitrogen to a good legume pasture. At the beginning of the second season the previous plots of fallow, beans, subterranean clover and medic had 36,27, 14 and 12 mm more water in the top metre of soil than oat plots. Cereals after oats apparently did not respond to fertilizer nitrogen because of the dry conditions, but on other plots the yield response was not proportional to the additional water. Although first year treatments affected growth of the three cereals in the second season, the new cereal, triticale, showed no evidence of different adaptation to growing conditions than wheat or barley. The effects of first and second year treatments carried through to the wheat crop in the third season. There were marked differences in nitrogen availability, but evidence that the second crop was depleting soil nitrogen reserves. Nitrogen from first year legume residues was available earlier in the season than second year fertilizer nitrogen which had been leached from the surface soil.



Sign in / Sign up

Export Citation Format

Share Document