摘要 :
Single and coastal superphosphates are equally effective as sulfur fertilisers for subterranean clover on very sandy soils in high rainfall areas of south-western Australia
M. D. A. Bolland, J. S. Yeates and M. F. Clarke
Abst...
展开
Single and coastal superphosphates are equally effective as sulfur fertilisers for subterranean clover on very sandy soils in high rainfall areas of south-western Australia
M. D. A. Bolland, J. S. Yeates and M. F. Clarke
Abstract
To reduce leaching of phosphorus (P) from fertilised pastures to shallow estuaries in the high rainfall (>800 mm annual average) areas of south-western Australia, and to supply extra sulfur (S) for subterranean clover (Trifolium subterraneum L.) in pasture, 'coastal superphosphate' was developed as a possible alternative P and S fertiliser to single superphosphate. Coastal superphosphate is made by adding phosphate rock and elemental S to single superphosphate as it comes out of the den before granulation. It has about 3 times more sulfur (S) and one-third the water-soluble P content than single superphosphate. Four long-term (5-year) field experiments were conducted in south-western Australia to compare the effectiveness of single and coastal superphosphate as S fertilisers for subterranean clover pasture grown on very sandy soils that are frequently S deficient after July each year due to leaching of S from soil. Seven different amounts of S were applied as fertiliser annually. Fertiliser effectiveness was assessed from clover herbage yield and S concentration in dried herbage. Fertiliser nitrogen was not applied in these experiments as this was the normal practice for pastures in the region when the research was conducted.
Both coastal and single superphosphates were equally effective per unit of applied S for producing dried clover herbage and increasing S concentration in herbage. Previous research on very sandy soils in the region had shown that coastal superphosphate was equally or more effective per unit of applied P for production of subterranean clover herbage. It is, therefore, concluded that coastal superphosphate is a suitable alternative S and P fertiliser for clover pastures on very sandy soils in the region. The concentration of S in dried clover herbage that was related to 90% of the maximum yield (critical S) was about 0.20–0.35% S during August (before flowering) and 0.15–0.20% S during October (after flowering).
收起
摘要 :
Borogypsum, formed during the production of boric acid, is discharged improperly or dumped into privately constructed dams, which contributes to environmental pollution. On the other hand, production of fertilizers containing bori...
展开
Borogypsum, formed during the production of boric acid, is discharged improperly or dumped into privately constructed dams, which contributes to environmental pollution. On the other hand, production of fertilizers containing boric acid and boron is an expensive process. The utilization of the waste borogypsum in the production of boron-containing fertilizers was investigated in this study. Fertilizers obtained from wastes are highly beneficial for the environment, and additionally, they contain phosphorus, nitrogen, sulfur, calcium, and boron. Thus, industrial scale production of boron-containing fertilizers from borogypsum is an economically novel and environmentalfriendly approach. This study aims at investigating the possible utilization of borogypsum for triple superphosphate production at the laboratory scale. The results of the study illustrate that it is possible to use waste borogypsum for production of triple superphosphate in a continuous-flow process. Thus, utilization of borogypsum is not only an alternative process but also allows the protection of the environment from fluorine and borogypsum wastes.
收起
摘要 :
Fosfat adalah salah satu unsur hara yang sangat dibutuhkan oleh semua jenis tanaman untuk memacu perkembangan akar, batang, bunga, dan buah menjadi lebih cepat. Kekurangan fosfat dapat menyebabkan tanaman akan tumbuh kerdil, daun ...
展开
Fosfat adalah salah satu unsur hara yang sangat dibutuhkan oleh semua jenis tanaman untuk memacu perkembangan akar, batang, bunga, dan buah menjadi lebih cepat. Kekurangan fosfat dapat menyebabkan tanaman akan tumbuh kerdil, daun berwarna hijau tua, anakan sedikit, pemasakan lambat dan sering tidak menghasilkan buah. Pupuk TSP (Triple Superposphate) merupakan jenis pupuk anorganik multi-komponen yang memiliki kandungan komponen hara N atau P secara parsial yang lebih besar jika dibanding dengan pupuk NPK. Bahan baku utama yang digunakan untuk membuat pupuk TSP ini adalah batuan fosfat. Pemilihan proses untuk memproduksi pupuk TSP perlu dianalisis agar produksi yang dihasilkan lebih optimal. Pupuk TSP dapat diprodiksi melalui dua macam proses, yaitu proses Odda dan Dorr-Oliver. Pada proses Odda, digunakan bahan baku berupa batuan fosfat dan asam nitrat atau asam klorida. Sedangkan pada proses Dorr-Oliver, digunakan bahan baku berupa batuan fosfat dan asam fosfat. Dari studi yang telah dilakukan, proses Odda lebih dipilih karena ditinjau dari aspek bahan baku, konversi, kondisi operasi, dan ekonomi, proses Odda lebih baik daripada proses Dorr-Oliver. Dengan desain umur pabrik selama 30 tahun, didapatkan Internal Rate of Return (IRR) sebesar 18.6% yang dimana nilainya lebih besar dari bunga pinjaman bank sebesar 9.18%. Kemudian didapatkan Pay Out Time (POT) sebesar 5.1 tahun dan Break Even Point (BEP) sebesar 26%.
收起
摘要 :
There is little information available about the impact of nitrogen and phosphorus fertilization on the uptake of metals by Atriplex plants. A series of pots experiments were conducted to define the metals uptake response of four A...
展开
There is little information available about the impact of nitrogen and phosphorus fertilization on the uptake of metals by Atriplex plants. A series of pots experiments were conducted to define the metals uptake response of four Atriplex species to urea (U) and superphosphate (SP) fertilization. The studied Atriplex species were river saltbush (Atriplex amnicola), wavy saltbush (Atriplex undulata), quail saltbush (Atriplex lentiformis), and old man saltbush (Atriplex nummularia). The growth and metals uptake of Atriplex species were significantly (P < 0.05) affected by the fertilizer treatments. U reduced the soil pH by 10% compared to the control. SP reduced the availability of Zn, Pb, and Cd by 24, 16, and 28% compared to the control. U increased the shoots Zn and Pb by 16 and 20% compared to SP. The combined application of U+SP reduced the Zn and Pb concentrations in the shoots by 10 and 13% compared to U alone. U increased the root-to-shoot transfer of Zn and Pb by about 30 and 49%. Root phosphorus (P) and calcium (Ca) limit the translocation of metals to the Atriplex shoots and this may be by the precipitation of the metals in the roots. The study clearly showed that it is feasible to apply P fertilizer to alleviate root-to-shoot transfer of Zn and Pb. Moreover, pure N application should be avoided to minimize the occurrence of high levels of Zn and Pb in the Atriplex shoots.
收起
摘要 :
The need to manage the potentially biotoxic metal-cadmium (Cd) in soil, relative to proposed limits, requires knowledge of how much Cd is present naturally under minimally disturbed conditions (MDC). Two data sets were collated, o...
展开
The need to manage the potentially biotoxic metal-cadmium (Cd) in soil, relative to proposed limits, requires knowledge of how much Cd is present naturally under minimally disturbed conditions (MDC). Two data sets were collated, one of MDC soils sampled under native bush (n=293) and another of different land uses (arable, dairy, drystock, horticulture, forestry, and urban; n=1043) from which was estimated the background and anthropogenic contributions of Cd. The concentration of total Cd in MDC soils was strongly correlated to 11 different variables (e.g. pH, total carbon), but to total phosphorus most of all (r = 0.712, P < 0.001). Phosphorus concentration was used in an equation to show on average that background concentrations (up to a maximum of the 95th percentile of the MDC data set; 0.48 mg kg(-1)) accounted for about half of the Cd in the land use data set. The New Zealand fertiliser management strategy currently sets absolute limits - irrespective of soil type or background contributions. However, given that anthropogenic inputs of Cd have been shown to be more bioavailable to plants, our approach could be used to highlight and initiate further investigation of anthropogenic enrichment that is more soil specific
收起
摘要 :
A field experiment was conducted during kharif, 2001 and 2002 to study the relative efficacy of phosphocompost and single superphosphate in soybean [Glycine max (L.) Merrill] genotypes. Application of single super phosphate led to...
展开
A field experiment was conducted during kharif, 2001 and 2002 to study the relative efficacy of phosphocompost and single superphosphate in soybean [Glycine max (L.) Merrill] genotypes. Application of single super phosphate led to higher yield by 16.2% over phosphocompost, which in turn produced significantly higher yield (19.8%) than no P - control. Among genotypes, JS 335 recorded highest yield, which was higher to the tune of 9.4% over PK 416, 18% over PK 1029 and 21.4% over Ahilya 4. Growth and yield attributes followed the trend similar to that of yield. The highest protein and oil yield were associated with JS 335 followed by PK 416. The maximum protein and oil yield were recorded with the application of single superphosphate. Application of single superphosphate was found the most productive and cost effective source of phosphorus in soybean.
收起
摘要 :
Experiments were conducted during summer (March 1995), early rainy (August, 1995) and late rainy (October, 1995) seasons on 12 year old 'Alphonso' mango trees raised under rainfed condltions to study the comparative efficiency of ...
展开
Experiments were conducted during summer (March 1995), early rainy (August, 1995) and late rainy (October, 1995) seasons on 12 year old 'Alphonso' mango trees raised under rainfed condltions to study the comparative efficiency of placement method and time of application on phosphorus absorption using ~(32)p labelled single superphosphate. Five hundred grams of the labelled superphosphate (0.1 to 0.2 mCi or 3.7 to 7.4 mBq of activity per g of P) per plant along with recommended level of N (500 g) and K (375 g) was placed in 5 cm deep and 30-60 cm wide trenches. Phosphorus derived from fertilizer (Pdff%) was monitored at 30, 45 and 60 days after fertilizer application from ~(32)p activity In the leaf. In summer and early rainy seasons the zone of the highest phosphorus absorption was between 90 and 150 cm. In the late rainy season this zone moved closer to the tree trunk (60 and 120 cm radial distance). Thus, the fertilizer placement in mango between radial distances of 90 - 150 cm during summer and early rainy season (March-August) and between 60-120 cm during late rainy season would result in better absorption of the applied fertilizer.
收起
摘要 :
The main objective of this study was to improve the growth of oil palm seedlings by using microbe plus to enhance phosphorous availability from rock phosphate under oil palm nursery was evaluated at Oil Palm Research Institute of ...
展开
The main objective of this study was to improve the growth of oil palm seedlings by using microbe plus to enhance phosphorous availability from rock phosphate under oil palm nursery was evaluated at Oil Palm Research Institute of Ghana, Kade-Kumasi. The study consisted of 16 treatments replicated 3 times in a 4 × 4 factorial experiment arranged in Randomize Complete Block Design. The factors tested were: Phosphate fertilizers (Phosphate only, triple superphosphate, super rock phosphate and Togo rock phosphate) and microbe plus rates (0, 50, 100 and 150%). Data was collected on leaf area, leaf area index and dry matter production. All data obtained were subjected to analysis of variance (ANOVA) using GENSTAT Version 11.1 (2008). The results showed that the P fertilizers and microbe plus applied alone or their interactions had no significant (P=.05) effect on leaf area and leaf area index values, however, dry matter produced was significantly (P=.05) different from each other. TSPMP150 treated seedlings produced significantly (P=.05) the highest dry weight; 42% increase over the control (No phosphate and microbe plus). The complementary use of microbe plus with triple superphosphate or Senegal rock phosphate proved to be the best options in terms of the parameters measured than the triple superphosphate. Microbe plus can therefore be used in combination with rock phosphate to improve phosphate availability. Field experiment is suggested to validate the effect of microbe plus and these rock phosphates on the performance of oil palm, whereas, additional studies with different application rates, both at nursery and at the field, are recommended.
收起
摘要 :
Soil phosphorus (P) sorption is an important and relatively stable soil property which dictates the equilibrium between sorbed and solution P. Soil P sorption measures are commonly adjusted for the effect of current P fertility on...
展开
Soil phosphorus (P) sorption is an important and relatively stable soil property which dictates the equilibrium between sorbed and solution P. Soil P sorption measures are commonly adjusted for the effect of current P fertility on the amount of P a soil sorbs. In the case of highly fertilised agricultural soils, however, this adjustment is likely to be inappropriate as it may mask changes in a soil’s capacity to sorb P, which could affect future P fertiliser applications. A study was undertaken to compare adjusted or unadjusted methods of measuring P sorption using 9 pasture soils sampled from southern Victoria which had previously received P fertiliser and lime. The P sorption assessment methods included: P sorption isotherms, P-buffering capacity (PBC) measures (slope between equilibrium P concentration of 0.25 and 0.35 mg P/L), and single-point P-buffering indices (PBI), with methods either adjusted or unadjusted for current P fertility. A single application of 280 kg P/ha, 6 months before sampling, resulted in a general negative displacement of unadjusted P sorption isotherm curves, indicating reduced P sorption on 8 of the 9 soils. Adding the Colwell extractable P concentration to the amount of P sorbed before calculating the slope (PBC+ColP), tended to negate this fertiliser effect and, in 2 of the 9 soils, resulted in a significant increase in PBC+ColP values. Increasing rates of P fertiliser application (up to 280 kg P/ha) resulted in a consistent trend to decreasing PBI values (unadjusted for Colwell P), which was significant at 4 of the 9 sites after 6 months. However, only minimal changes in PBI values were determined when PBI was adjusted for current P fertility (PBI+ColP). Phosphorus sorption properties appeared reasonably stable over time, although 2 soils, both Ferrosols, indicated significant linear increases in PBI values when these sites remained unfertilised for 30 months. Lime significantly increased both PBI and PBI+ColP values at all sites 6 months after application, but the effect generally diminished after 30 months, suggesting PBI measurements should not be taken immediately after liming.
These results demonstrate that unadjusted measures of P sorption are more likely to accurately reflect changes in soil P sorption capacity following P fertiliser applications and suggest that the unadjusted PBI be used in commercial soil testing rather that the currently adjusted PBI+ColP.
收起
摘要 :
Groundnut is an important food and cash crop for smallholder farmers in Eswatini. However, its yield is very low partly due to poor soil fertility particularly calcium and phosphorus deficiencies associated with soil acidity. Thus...
展开
Groundnut is an important food and cash crop for smallholder farmers in Eswatini. However, its yield is very low partly due to poor soil fertility particularly calcium and phosphorus deficiencies associated with soil acidity. Thus, a field experiment was conducted to determine the effects of different inorganic fertiliser types on growth and yield of groundnut. The treatments were: a control with no fertiliser, [2:3:2 (22) at 300 kg ha-1], single superphosphate (100 kg ha-1), calcium nitrate (120 kg ha-1) and a combination of calcium nitrate (120 kg ha-1) and single superphosphate (100 kg ha-1). A randomised complete block design (RCBD) with three replications was used. Results showed highly significant (p<0.01) differences among the fertiliser types on most of the growth parameters recorded. At 90% flowering, significantly highest number of leaves per plant (48.3), the tallest plant (42.17 cm), the highest canopy width (41.47 cm), the highest number of branches per plant (6.57) and plant dry biomass per plant (20.6 g) were recorded for treatments with calcium nitrate followed by the application of combination of calcium nitrate and single superphosphate. Similarly, most of the yield components and yield were significantly (p<0.05) affected by the fertiliser types. Significantly highest numbers of total pods per plant (28.8), mature pods per plant (26.9), dry pod yield (950.6 kg ha-1), hundred seed mass (82.8 g), shelling percentage (70.6) and seed yield (671.6 kg ha-1) were recorded from a combination of calcium nitrate and single superphosphate fertiliser. Thus, combined application of 120 kg ha-1 calcium nitrate and 100 kg ha-1 single superphosphate fertilisers can be used to increase the productivity of groundnut in the study area.
收起
原文获取