Effect of rock phosphate and superphosphate on crop yield and soil phosphorus test in long‐term fertility plots

Abstract

A long‐term (1968–1987) field study using corn‐soybean in rotation was conducted to compare the effect of rock phosphate (RP) and superphosphate (SP) at two lime levels on crop yield, soil available phosphorus (P) as Bray P‐1 (0.025M HCl + 0.03M NH₄F) and Bray P‐2 (0.1M HCl + 0.03M NH₄F) tests, and on the relationship between crop yield and available P tests. Treatments included a control, application of RP and SP ranging from 12 to 96 kg P₂O₅ ha^‐1 yr^‐1, and combinations of RP with SP or sulphur at various rates. The RP was applied once in 1968 at 8 times the annual rate while SP was applied annually until 1985. Corn and soybean yields increased with P application, more with SP than with RP. Bray P‐l and Bray P‐2 increased linearly with the amount of P applied as SP or RP. A significant correlation (r > 0.64) was found between corn yield and Bray P‐2 at low lime level with both P sources. In contrast, a poor correlation (r < 0.50) was found between soybean yield and soil P tests. Both RP and SP were effective sources of P fertilizers for corn on soils treated with a small amount of lime compared with a large amount of lime. Under low lime the Bray P‐2 accounted for 41% and 66% variability in com yield with applied RP and SP, respectively. On the other hand, Bray P‐1 was only of value when SP was the source of P.     

Soybean pod wall P and K as related to extractable P and K and grain yield

Abstract

It was proposed that the pod wall surrounding the developing soybean seed (growth stage R6) could serve as a diagnostic indicator of crop nutritional status. This was evaluated by summarizing soybean responses (R1 trifoliate and R6 pod wall P and K concentrations, and yield) to various levels of soil P and K availability in ten field experiments. Pod wall P and K concentrations were closely related to available soil P (Bray P₁) and K (MNH₄C₂H₃O₂‐pH 7.0), respectively. The relationship of pod wall P concentration to grain yield was superior to those found when either trifoliate leaf P or available soil P was related to grain yield. Pod wall K was similarly superior to leaf K or available soil K. Though further work is needed to describe changes in pod wall composition during grain‐fill, it appears that pod wall sampling offers an alternative or additional sampling interval in the evaluation of soybean nutrition     

长期施氮、磷、钾化肥对玉米产量及土壤肥力的影响

以1990年建立的国家褐潮土土壤肥力与肥料效益长期监测基地(北京昌平站)的长期肥料定位试验为研究平台,研究了不同施肥制度对玉米产量和土壤肥力的影响。结果表明,长期均衡地施NPK肥或NPK与有机肥配施,可以显著提高玉米产量和土壤有机质、全氮、全磷、速效氮、速效磷、速效钾等肥力指标,并能提高土壤微量元素的含量;而不均衡施肥(N、NK、NP、PK)导致相应的营养元素的耗竭。相关分析表明,在褐潮土上增施磷肥和有机肥对提高玉米产量具有重要的作用。     

Wheat p requirements on calcareous Morrocan soils: III evaluation by isotherms compared to Olsen extractable P

Abstract

Phosphorus fertilizer recommendations were compared by interpretations from P isotherms, Olsen extractable P and the Mitscherlich‐Bray model based on the Olsen method for 15 soils from the Chaouia (dryland) region of Morocco. The P isotherms were fit to straight line and second degree polynomial equations. The P buffer indexes (PBI) derived from the isotherms were not significantly correlated to P buffer capacities as measured by a single P buffer capacity index, but negatively correlated to Olsen P (r = ‐0.63), relative yield (r = ‐0.76) and P uptake (r = ‐0.66). Phosphorus in solution was a quadratic function of P added in 0.01 M CaCl₂equilibrium solution. The P fertilizer recommendations to maintain soil solution P concentrations at 0.01, 0.12 and 0.20 mg P L^‐1were higher than recommended by direct interpretation of plant response to Olsen extractable P and the quantity based on the Mitscherlich‐Bray model as calculated from Olsen available P values. The P fertilizer recommended to maintain soil solution P of 0.10 mg P L^‐1was significantly correlated with Olsen P (r = 0.71) as was that recommended Mitscherlich‐Bray log transformation model (r = 0.81), and nonlinear least square estimation (r = 0.78). Field research will be needed to evaluate if the P fertilizer recommended to maintain this solution P concentration is adequate for maximum economic wheat grain yield under field conditions     

Potassium‐fertilizer management in winter oilseed‐rape production in China

Optimal potassium (K) fertilization is beneficial for oilseed‐rape (Brassica napus L.) yield and quality. However, the discrepancy between the high K demand of winter oilseed rape and low soil fertility and insufficient potassium input has limited the sustainable development of oilseed‐rape production. A series of on‐farm experiments in the key winter oilseed‐rape domains of China was conducted from 2004 to 2010 to evaluate K‐fertilizer management for winter oilseed rape. Currently, the average NH₄OAc‐extractable K content in the 0–20 cm soil layer is 89.1 mg kg^–1 indicative of “slight deficiency”. In addition, farmers in China usually fail to use sufficient K fertilizer in oilseed‐rape production, the average mineral‐potassium‐fertilizer input in 2010 being only 35 kg K ha^–1, far lower than the recommended rate of potassium for winter oilseed rape. Adequate potassium fertilization significantly raises seed yield. The average yield‐increase rate for the major production regions due to K‐fertilizer application was 18.5%, and the average K fertilizer–use efficiency 36.1%. Based on the negative correlation between yield response to potassium fertilization and available soil K content, a soil‐K‐test index was established for winter oilseed rape with a threshold value for NH₄OAc‐extractable soil K of 135 mg kg^–1. When available soil K‐content is below this threshold value, more K fertilizer should be applied to achieve high seed yield and to increase soil fertility. The major challenge for K‐fertilizer management in winter oilseed‐rape production in China will be to guide farmers in the different regions in making reasonable use of K fertilizer through soil K‐testing technology in order to maintain both seed yield and soil fertility.     

Effect of phosphorus,nitrogen fertilization and foliar applied manganese on yield and nutrient concentration of soybean

Abstract

A greenhouse experiment was conducted on clay loam soil of pH 7.8 to evaluate the effect of P, N fertilization and foliar applied Mn on yield and nutrient concentration in leaves and seeds of soybean. A significant yield increase was obtained for each added increment of P fertilizer up to 30 kg P₂O₅/acre. At application rates of 0, 15, 30 & 45 kg P₂O₅/acre, the seed yield was subsequently 27.8, 65.8, 82.8 & 83.6% of the maximum yield obtained at the maximum calculated P level. The yield increase accounted 14.2 and 10.2% for N and Mn applications. In all treatments, in which P was combined with N, the seed yield was relatively higher than with P or N applied alone.

Phosphorus, N and Mn content in leaves and seeds were positively correlated with the applied nutrient fertilizers. At any given level of applied P and Mn, P content was significantly higher in +N than ‐N treatments. By Mn application, P content in leaves and seeds was decreased. Phosphorus and Mn applications did not influence N content in leaves and seeds.     

Phosphate fertilizer compounds in soils: Their influence on the relationship between plant yield and soil test value

Abstract

A pot experiment with a lateritic soil measured the relative effectiveness of monocalcium phosphate (MCP) fertilizers and six phosphate (P) compounds which were used to represent fertilizer compounds that may be present in soils. The P compounds were added at various rates, wheat was grown, and the treated soils were extracted with eight standard soil P‐test reagents. The relative effectiveness (RE) values for the fertilizer compounds based on plant yield were 1.00, 0.33, 0.32, 0.20, 0.16, 0.15, and 0.09 for MCP, P sorbed on gibbsite (Gi‐P), P sorbed on goethite (Go‐P), P sorbed on calcite (Ca‐P), AlPO₄ (Al‐P), Apatite (Ap‐P) and FePO₄ (Fe‐P), respectively. For soil treated with Ap‐P, Gi‐P, Go‐P, Ca‐P, and MCP, soil test values were significantly related to the yield of wheat. Only Bray 1, Bray 2, ammonium oxalate, and Colwell soil tests adequately predicted yield for Al‐P treated soil, and no soil test was suitable for soil treated with Fe‐P. Where soil tests were predictive of yield, separate calibrations were required for the different P compounds. For example, in order to obtain 100 mg of wheat per pot from soil that was treated with Al‐P, Fe‐P, Ap‐P, Gi‐P, Go‐P, Ca‐P, and Bray 2 soil test values of 122, 8, 387, 112, 9, 202, and 50 ug/g, respectively, were required.     

A preliminary comparison of the ammonium acetate‐edta soil phosphorus extraction method to the bray‐1 and olsen soil phosphorus extraction methods

Abstract

The ammonium acetate (NH₄OAc)‐EDTA soil phosphorus (P) extraction method was compared to either the Bray‐1 soil P extraction method for non‐calcareous soils or the Olsen soil P extraction method for calcareous soils to predict com and wheat plant tissue P concentration and grain yield responses. The NH₄OAc‐EDTA method predicted yield and tissue P concentration responses to P fertilizer applications more accurately than the Olsen method at three of five sites. Both the Bray‐1 and NH₄OAc‐EDTA methods were successful in predicting corn and wheat yield responses to P fertilizer applications in non‐ calcareous soils in many locations. However, a direct comparison of extracted soil P levels showed that the NH₄OAc‐EDTA method extracted soil P at levels which were more closely related to the Bray‐1 method than the Olsen method.     

Correlation of soil test nitrogen with potato yields

Abstract

Yield response of Idaho Russet Burbank potatoes to nitrogen fertilizer was related to soil test for inorganic N (NO₃ ^‐ and NH₄ ⁺) in a total of 27 field experiments over a 3‐year period using polynomial correlation and regression analysis. Nitrate plus ammonium nitrogen content in the surface foot of soil was found to be useful in predicting yield response of potatoes to applied nitrogen.

Correlations between yield and extractable N were considerably better when the data from each cropping system were analyzed separately than when all locations were analyzed as one group. Additional improvement was obtained by including extractable ammonium nitrogen and nitrogen in the second foot of soil respectively. The best correlation with yield was found using (NO₃ ^‐ + NH₄ ⁺)‐N in the surface foot following grain and the top two feet following non‐grain crops with R² values of 0.875 and 0.821 respectively.     

Coffee‐husk biochar application increased AMF root colonization,P accumulation,N2 fixation,and yield of soybean grown in a tropical Nitisol,southwest Ethiopia

Low soil fertility and soil acidity are among the major bottlenecks that limit agricultural productivity in the humid tropics. Soil management systems that enhance soil fertility and biological cycling of nutrients are crucial to sustain soil productivity. This study was, therefore, conducted to determine the effects of coffee‐husk biochar (0, 2.7, 5.4, and 16.2 g biochar kg^?1 soil), rhizobium inoculation (with and without), and P fertilizer application (0 and 9 mg P kg^?1 soil) on arbuscular mycorrhyzal fungi (AMF) root colonization, yield, P accumulation, and N₂ fixation of soybean [Glycine max (L.) Merrill cv. Clark 63‐K] grown in a tropical Nitisol in Ethiopia. ANOVA showed that integrated application of biochar and P fertilizer significantly improved soil chemical properties, P accumulation, and seed yield. Compared to the seed yield of the control (without inoculation, P, and biochar), inoculation, together with 9 and 16.2 g biochar kg^?1 soil gave more than two‐fold increment of seed yield and the highest total P accumulation (4.5 g plant^?1). However, the highest AMF root colonization (80%) was obtained at 16.2 g biochar kg^?1 soil without P and declined with application of 9 mg P kg^?1 soil. The highest total N content (4.2 g plant^?1) and N₂ fixed (4.6 g plant^?1) were obtained with inoculation, 9 mg P kg^?1, and 16.2 g biochar kg^?1 soil. However, the highest %N derived from the atmosphere (%Ndfa) (> 98%) did not significantly change between 5.4 and 16.2 g kg^?1 soil biochar treatments at each level of inoculation and P addition. The improved soil chemical properties, seed yield, P accumulation and N₂ fixation through combined use of biochar and P fertilizer suggest the importance of integrated use of biochar with P fertilizer to ensure that soybean crops are adequately supplied with P for nodulation and N₂‐fixation in tropical acid soils for sustainable soybean production in the long term.     

Effect of split applications of nitrogen fertilizer on the growth and nitrogen composition of Chinese mustard

Abstract

We assessed the effect of split applications of nitrogen (N) fertilizer on the growth and N composition of Chinese mustard. There were six treatments in which various rates of N fertilizer were applied as a basal dressing and two top dressings. The plants were harvested 40 days after seeding and the N composition of the plants determined. The soil was also sampled and the pH, electrical conductivity (EC) of 1:1 soil:water ratio extract, organic matter, nitrate‐nitrogen (NO₃‐N), Bray Pl‐extractable phosphorus (P) as well as 1N neutral ammonium acetate‐extractable potassium (K), calcium (Ca), and magnesium (Mg) concentrations after harvesting of the plants determined. The results show that there was no significant difference in yield from the various treatments. Total N concentration in shoots receiving the 1–2–1 fertilizer treatment was higher than that of the other treatments. However, NO₃‐N, soluble reduced N, and insoluble N concentrations in shoots as well as NO₃‐N, soluble reduced N, insoluble N, and total N concentrations of roots were not significantly different due to the treatments.     

Evaluation of N,P, S and B fertilization of Kentucky bluegrass seed in northern Idaho

Abstract

Current nitrogen (N) fertilizer recommendations for Kentucky bluegrass (Poa pratensis L.) seed production in northern Idaho are based on potential yield and annual precipitation. Soil test correlation information collected for other northern Idaho crops provide the basis for P, S and B recommendations. The objective of this paper is to assess the current recommendations with a series of forty field trials conducted on ten sites during four seed production seasons. All field trials were conducted on Alfisols and Mollisols initially containing less than 60 kg N/ha, 3.5 μg/g NaOAc extractable P, 40 kg extractable SO₄‐S/ha and 0.5 μg/g extractable B. Fertilization rates evaluated included: 0, 50, 75, 100, 125, 150 and 200 kg N/ha; 0, 30 and 60 kg P₂O₅/ha; 0, 25, and 50 kg SO₄‐S/ha, and 0 and 1.5 kg B/ha. Five field sites contained the cultivar ‘Argyle’ Kentucky bluegrass seed, while the other five sites contained the cultivar ‘South Dakota’.

Excellent relationships between percent maximum Kentucky bluegrass seed production and the sum of inorganic soil N + fertilizer N applied were observed for the ‘Argyle’ (R²=0.65) and ‘South Dakota’ (R²=0.72) cultivars. Phosphorus applications of 30 kg P₂O₅/ha improved seed yields from 10.0 to 51.6% when initial soil test values were less than 3.0 6 μg/g NaOAc extractable P. When initial SO₄‐S soil values were less than 32 kg/ha fertilizer additions increased seed yields from 12.6 to 107.3%. Boron applications did not improve seed yields. Analysis of these trials indicates that adequate information is available to make satisfactory P, S and B fertilizer recommendations; however, additional soil test correlation information is needed for N recommendations.     

Effect of annual applications of pelletized dolomitic lime on soil chemical properties and grass productivity

Lime in pelletized form is potentially more convenient for farmers than ground limestone, as it can be applied using conventional fertilizer‐spreading equipment. Pelletized lime is intended to maintain an optimum soil pH when applied annually at a rate of 350 kg lime/ha/yr. Interactions between lime and N fertilizer rate were examined by applying 0, 75, 150, 225 and 300 kg N/ha/yr (as calcium ammonium nitrate) in combination with 0, 175, 350 and 525 kg pelletized dolomitic lime/ha/yr over 3 yr to a permanent grassland sward used for silage production in County Down, Northern Ireland. Equal rates of ground lime, from the same source as the pelletized lime, were applied as a comparison. Effects on soil chemical properties, grass dry matter (DM) yield and herbage nutrient removal were examined. Lime maintained or slightly increased the soil pH, particularly in the top 2.5 cm of the profile, but there was no difference in the performance of pelletized lime compared to ground lime in any of the parameters measured. Lime had no significant effect on grass DM yield or grass quality; however, there was a significant (P < 0.05) reduction in yield at the first cut, particularly in year 2, when the highest lime rate (525 kg lime/ha/yr) was applied in the absence of N fertilizer. The dolomitic nature of the lime (11% Mg) resulted in significant (P < 0.001) increases in soil and herbage magnesium levels, and this could be beneficial for reducing the incidence of grass tetany in grazing animals. The P content of the herbage was also significantly higher in plots receiving lime, which suggests that lime may have enhanced the mineralization of P or stimulated root growth.     

Effects of salts on dry matter yield and nitrogen and phosphorus contents of rice plants

Abstract

The effects of different kinds and concentrations of salts on dry matter yield and nitrogen (N) and phosphorus (P) contents of rice plants under greenhouse conditions were determined for two silt loam soils, one from southern Ohio (Clermont) and one from Arkansas (Crowley). Yield and N and P contents tended to be enhanced by low salt concentration but to be depressed at higher concentration. The chloride salts (NaCl, CaCl₂) were most detrimental to yield and N and P contents, while the sulfate salts (especially Na₂SO₄,) were beneficial when the electrolyte concentration and P in the soil were not high.

The degree of adverse response to salts in the irrigation water and of favorable response to P fertilizer were reflected in the levels of electrolyte and available P in the soils studied. Total N content of the rice tissue increased much more from N and P additions than did total P content. The NaCl (1.5 mmhos/cm) and NaCl + Na₂SO₄ (3.0 mmhos/cm) salt treatments vere generally least detrimental, and NaCl and NaCl + CaCl₂both at 3.0 mmhos/cm were most detrimental to yield and N and P contents of tissue.

In the non‐lethal response range, salt‐depression of yield and N and P contents of tissue may well be largely or partially overcome by fertilizer application. In this study, the best combination of fertilizer and salt was the highest level of N (268 kg N/ha) and intermediate level of P (67 kg P/ha), in combination with NaCl + Na₂SO₄.     

Grape response to phosphorus fertilizer: Petiole to blade P ratio as a guide for fertilizer application

Abstract

A two‐year fertilizer study on a mature vineyard of grapes (Vitis vinifera L., cv. ‘Cabernet Sauvignon’ and ‘Sauvignon blanc') was conducted on a White House sandy loam (fine, mixed, thermic Ustollic Haplargid) soil at the University of Arizona Oracle Agricultural Center. Two cultivars were grown and treated with different levels of N and P fertilizer and tested for total P and NO₃‐N content of plant tissues.

Available P was evaluated with two extracting methods (Olsen and Bray P₁). Relationships between soil pH, extractable Al, Fe, Mn, and Zn with the availability indexes of soil P were also examined. Furthermore, the effects of P rates and placement on the P content of plant tissue, grape yield, and petiole to blade P ratios were investigated. Three fertilizer placements (0, 25, and 50 cm depths) at rates of 88 g P and 80 g N per vine were used for both cultivars in 1987, whereas, in 1988, three P rates (0, 88, and 176 g P per vine) and 207 g of N per vine were applied.

The results of this investigation indicated that fertilizer placement did not have a significant effect on grape yield nor the P content of petioles or leaf blades. Nevertheless, P fertilization of grapes resulted in a significant increase in plant P content and grape yield. Petiole to blade P ratio proved to be a suitable indicator for diagnosis of P status of grape plants.     

Variation in content of available P and K (bray I) in soil samples from a cropped N,P, and K fertility experiment over 8 years

Abstract

Plots from a N, P, and K field fertility experiment were soil sampled each spring and fall from 1971 to 1979 to study the effect of cropping and different rates of added P and K on the content of available soil P and K (Bray I). Phosphorus and K fertilization was in the spring after soil sampling and before planting in 1971, 1972,and 1973 and in the fall after sampling in 1974, 1975, 1976, 1977, and 1978. Over the 8‐year period, available soil P increased 1 kg/ ha for every 2.3 kg/ha of added P; while available soil K increased 1 kg/ha for every 5.7 kg/ha of added K. However, within a growing season and between growing seasons, contents of available soil P and K showed cyclic patterns, increasing and decreasing to a greater extent than the long‐term response. Changes in available P and K from spring to fall and from fall to spring are presented. Variability in the content of available soil P and K for 32 plots receiving a similar treatment of either P or K was greater for P as compared to K.     

Foliar fertilization of soybeans (Glycine max L.)

Abstract

The effects of foliar fertilizer applications to soybeans during seed‐filling were examined using a complete factorial design with four levels each of nitrogen (N), phosphorus plus potassium (P+K) and sulfur (S). Hodgson soybeans were planted in 76‐cm rows on a Piano silt loam (Typic Argiudoll) in 1976 and 1977. Four fertilizer spray applications were made at 7‐ to 10‐day intervals beginning at stage R₄ ². The application of N generally increased yield, seed weight, and percent N in the grain both years of the experiment. Phosphorus, K, and S had little influence on the parameters measured. Leaf burn after each fertilizer application was significantly increased by most levels of fertilizer addition.     

Effect of Integrated Nutrition in Aromatic Rice on Carbon and Nutrient Status in an Inceptisol

Inorganic fertilizer-based nutrient management is the maintenance of soil fertility for sustaining increased crop productivity, but often at the cost of degrading soil health. This study was conducted to determine whether incorporation of organics in the conventional inorganic-based nutrient management practice on aromatic rice could sustain both fertility and soil organic carbon status on a silt loam Aeric Haplaquept. Addition of organic manure along with inorganic fertilizer could almost maintain organic carbon status of soil, while the treatment only with inorganic fertilizer registered a substantial decrease (6.58%) from its initial value. Among the treatment combinations, the treatment receiving 1 t ha^?1 mustard cake and inorganic fertilizer @ N₄₀P₂₀K₂₀ was the best, which registered the highest grain (3.01 t ha^?1) and straw (5.32 t ha^?1) yield of rice, highest nutrient uptake, and least decline in available N, P, and K status of soil. However, even the best treatment combination also was proved to be suboptimal in sustaining soil fertility.     

Reactive aluminum in the vermont soil test

Abstract

Determination of Reactive Al by extracting a soil sample with pH 4.8 NH₄ OAc (1.25 N acetate) characterizes for northern acid soils the quantity of soil acidity that must be neutralized to meet lime need and also lower the P adsorbing capacity. Extracted Al is used in conjunction with pH in 10 mM CaCl₂ to calculate the lime requirement directly. First, the amount of P fertilizer needed is approximated, based on the P intensity (Available P) determined in the same NH₄ OAc extract. Then the recommended amount is increased by a P‐fixation factor obtained from the Reactive Al measured, and decreased by a Reserve P factor derived from fluoride extractable P.

Unlike a buffer lime requirement method, which predicts lime needed to reach a target pH, the Reactive Al test estimates the quantity of acidity that must be neutralized to prevent fixation of P fertilizer by soil Al and to release P from Al‐bound sources. Attaining a particular target pH is not the primary goal. The Reserve P test measures the amount of unavailable Al phosphates that becomes partially available when lime needs are met.