Antônio de Goiás, Brazil b Soybean Center of Embrapa, Londrina, Brazil. Published online: 23 Nov 2011.

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1 This article was downloaded by: [ ] On: 09 January 2014, At: 03:30 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: Registered office: Mortimer House, Mortimer Street, London W1T 3JH, UK Communications in Soil Science and Plant Analysis Publication details, including instructions for authors and subscription information: Response of Soybean to Phosphorus Fertilization in Brazilian Oxisol N. K. Fageria a, A. Moreira b & C. Castro b a National Rice and Bean Research Center of Embrapa, Santo Antônio de Goiás, Brazil b Soybean Center of Embrapa, Londrina, Brazil Published online: 23 Nov To cite this article: N. K. Fageria, A. Moreira & C. Castro (2011) Response of Soybean to Phosphorus Fertilization in Brazilian Oxisol, Communications in Soil Science and Plant Analysis, 42:22, To link to this article: PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the Content ) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at

2 Communications in Soil Science and Plant Analysis, 42: , 2011 Copyright Taylor & Francis Group, LLC ISSN: print / online DOI: / Response of Soybean to Phosphorus Fertilization in Brazilian Oxisol N. K. FAGERIA, 1 A. MOREIRA, 2 AND C. CASTRO 2 1 National Rice and Bean Research Center of Embrapa, Santo Antônio de Goiás, Brazil 2 Soybean Center of Embrapa, Londrina, Brazil Introduction Soybean is an important grain crop for Brazil, and phosphorus (P) plays an important role in improving yield of this crop in Brazilian Oxisols. Data are limited on influence of P sources and rate on soybean yield, yield components, and P-use efficiency. A field experiment was conducted for 3 consecutive years to determine response of soybean to three fertilizers (single superphosphate, Yoorin, and Arad) with 0, 17.5, 35, and 52.5 kg Pha 1 (0, 40, 80 and 120 kg P 2 O 5 ha 1 ). Grain yield was significantly influenced by phosphorus fertilization. Overall, maximum grain yield was produced by application of single superphosphate, followed by Yoorin and Arad. Number of grains per pod and 100-grain weights were also influenced significantly by P fertilization. Shoot dry weight, number of pods per plant, and grain harvest index had a significant positive association with grain yield. Phosphorus uptake in grain was about six times more than uptake in shoots, and P uptake in grain had a significant positive association with grain yield. Phosphorus-use efficiency (kg grain/kg P applied or uptake) decreased with increasing P rate, and it was greater for single superphosphate than for Yoorin and Arad sources of P fertilization. However, P-utilization efficiency (kg grain plus straw yield / P uptake in grain plus straw) was greater under Yoorin treatment compared to the two other sources of P. Keywords Glycine max, grain harvest index, grain yield, P uptake Soybean is an important grain legume for Brazilian economy. It is one of the most important agricultural commodities for export as well as home consumption in the country. Soybean cultivation in Brazil started in the early 1970s in the southern part, especially in the State of Rio Grande do Sul, and rapidly expanded in the central part, locally known as the Cerrado region. Today, Brazil is the second largest producer of soybean after United States of America, followed by Argentina. The Brazilian Cerrado region is about 205 million ha, and Oxisols are the dominant soil group. These soils are commonly deep, well drained, and well structured, but they are acidic and very low in native fertility, especially phosphorus (P) (Fageria and Baligar 2008). The main reasons for P deficiency in these soils are low natural P level and high P-immobilization capacity (Fageria et al. 2004; Fageria and Breseghello 2004). When P Received 7 July 2010; accepted 17 September Address correspondence to N. K. Fageria, National Rice and Bean Research Center of Embrapa, Caixa Postal 179, Santo Antônio de Goiás, GO, CEP , Brazil. fageria@cnpaf.embrapa.br 2716

3 Phosphorus versus Soybean 2717 fertilizers are applied to replenish soil fertility of these soils, about 70 90% of the P fertilizers is adsorbed and becomes locked in various soil P compounds of low solubility, without any immediate contribution to crop production (Fageria and Baligar 2003). Recovery efficiency of applied soluble P fertilizers by annual crops during their growth cycle is less than 20% in most of the acidic soils (Fageria and Baligar 2003; Fageria et al. 2004). One of the strategies of improving P uptake and P-use efficiency by annual crops grown on Brazilian Oxisols is use of adequate rate and form of P fertilizer. There is limited information on use of different P sources and rates on soybean production in the State of Tocantins, in the central part of Brazil. The objective of this study was to determine the response of soybean crop to three sources and four rates of P fertilization. Materials and Methods A field experiment was conducting for 3 consecutive years at the Conquest Farm, Alvorada, Tocantins. The soil of the experimental area was an Oxisol with chemical attributes of ph 5.3, calcium (Ca) 0.54 cmol c kg 1, magnesium (Mg) 0.26 cmol c kg 1, aluminum (Al) 0.4 cmol c kg 1,P0.8mgkg 1, potassium (K) 41 mg kg 1, cooper (Cu) 1.3 mg kg 1,zinc (Zn) 0.6 mg kg 1, iron (Fe) 66 mg kg 1, manganese (Mn) 8 mg kg 1, and organic matter 9gkg 1. The textural analysis was clay content 403 g kg 1, silt content 40 g kg 1, and sand content 557 g kg 1. Soil analysis methods used in this study are described in a soil analysis manual published by Embrapa (1997). The treatments consisted of three P sources: simple superphosphate, Yoorin (thermophosphate), and Arad (rock phosphate). Simple phosphate was 8.7% P (20% P 2 O 5 ), Yoorin was 7.6% P (17.5% P 2 O 5 ), and Arad was 14.4% P (33% P 2 O 5 ). These phosphates were applied at 0, 17.5, 35, and 52.5 kg P ha 1. These rates correspond to 0, 40, 80, and 120 kg P 2 O 5 ha 1. These rates were applied as broadcast each year and incorporated into the soil. The experimental area received 600 kg ha 1 fertilizer ( Zn) in the band at sowing each year. The experimental area also received 3.75 Mg dolomitic lime ha 1 3 weeks before sowing the first crop as broadcast and incorporated. The liming material had 30.8% Ca, 18.5% Mg, and a neutralizing power of 97.2%. Experimental plots were 6 m 4 m. Experimental design was randomized complete block with three replications. Cultivar Sambaiba was planted in rows with spacing of 40 cm. The seeds were inoculated with Bradyrhizobium elkanil at sowing. At the time of harvest, a 1-m row of plants was harvested from each plot to determine number of pods, grain per pod, 100-grain weight, and shoot dry weight. Plant material was dried in an oven at about 70 C until constant weight and then ground for P determination. The P determination was done in straw and grain of first- and second-year materials. Ground material was digested with a 2:1 mixture of nitric and perchloric acids. The P concentration in the digest was determined colorimetrically. Phosphorus-use efficiency (years 1 and 2) was calculated by using the following equations (Fageria 2009): Agronomic efficiency (kg kg 1 ) = (Grain yield at a determined P rate Grain yield at zero P rate)/(quantity of P applied) Apparent recovery efficiency (%) = (P uptake ingrain plus straw at a determined P rate P uptakein grain plus straw at zero P rate)/ (Quantity of P applied)

4 2718 N. K. Fageria, A. Moreira, and C. Castro Utilization efficiency (kg kg 1 ) = Physiological efficiency apparent recovery efficiency Data were analyzed by analysis of variance (ANOVA) and Tukey s test, and regression analysis was performed whenever necessary. Results and Discussion Growth, Yield, and Yield Components Analysis of variance did not show significant interaction between year grain yield, year shoot dry weight, year number of pods per plant, and year grain harvest index (Table 1). Hence, results of these parameters across 3 years are presented. Nonsignificant interaction of these parameters indicates that response of soybean to P fertilization was similar in 3 years of cultivation. Phosphorus fertilization significantly increased grain yield of soybean. Grain yield varied from to kg ha 1 depending on source and rate of P application. Simple superphosphate rate of 52.5 kg P ha 1 (120 kg P 2 O 5 ha 1 ) produced significantly greater grain yield compared to other two sources and rates of P fertilization. Response of soybean to P fertilization in Brazilian Oxisol has been widely reported (Cordeiro et al. 1979; Sfredo et al. 1996; Bedin et al. 2003). Based on regression equations, maximum grain yield of 3712 kg ha 1 was achieved at 71 kg P ha 1 (163 kg P 2 O 5 ) applied through single superphosphate. Similarly, maximum grain yield of 3491 kg ha 1 was obtained with the application of 36 kg P ha 1 through Yoorin and 3979 kg ha 1 grain yield was obtained with the application of 296 kg P ha 1 through Arad phosphate. Based on these results, single superphosphate produced 52 kg grain yield per kg P applied, Yoorin produced 97 kg grain per kg P applied, and Arad produced 13 kg grain per kg P applied. This means that Yoorin (thermophosphate) was most efficient in grain yield production per unit of P application among the three P sources. Oliveira et al. (1984) studied relative efficiency of rock phosphate, triple superphosphate, and thermophosphate in soybean wheat rotation in a Brazilian Oxisol and reported that thermophosphate was more efficient in soybean and wheat production compared to rock and triple superphosphate. Ramos (1982) also reported that Yoorin thermophosphate had the same efficiency in soybean production as superphosphates. Shoot dry weight varied from to kg ha 1, with an average value of kg ha 1. Although, shoot dry weight was significantly (P = 0.05) influenced by P treatment, Tukey s test could not separate means of P sources and rates. Number of pods and grain harvest index were not influenced significantly by P treatment (Table 1). However, shoot dry weight, number of pods per plant, and grain harvest index had significant associations with grain yield (Table 2). This means that by increasing these parameters, soybean yield can be increased. Of the variability in grain yield, 19% was due to shoot dry weight, 44% was due to number of pods, and 25% was due to grain harvest index. Hence, the number of pods per plant had a greater influence in increasing grain yield compared to shoot dry weight and grain harvest index. Fageria et al (2006) and Fageria (2009) reported that in legumes, the number of pods had the most influence in increasing grain yield as compared to other yield components. Year number of grains per pod and year 100-grain weight interactions were significant (Tables 3 and 4). Hence, results of these parameters for 3 years are presented. Number of grains per pod was greater in the first year and decreased in the second and third years of cultivation. Across 3 years, number of grains per pod varied from 1.99 to 2.27 per pod. Yoorin and single superphosphate produced the most grains per pod, and Arad produced

5 Phosphorus versus Soybean 2719 Table 1 Grain yield, shoot dry weight, number of pods per plant, and grain harvest index as influenced by P source and rate P source and rate (kg ha 1 ) Grain yield (kg ha 1 ) Shoot dry wt. (kg ha 1 ) Number of pods per plant Grain harvest index Control (without P) c a Simple superphosphate abc a Yoorin abc a Arad bc a Simple superphosphate ab a Yoorin ab a Arad bc a Simple superphosphate a a Yoorin abc a Arad abc a Average Ftest Year (Y) Prate(P) NS NS Y P NS NS NS NS CV (%) ,, NS Significant at the 5% and 1% probability levels and nonsignificant, respectively. Notes. Means followed by the same letter in the same column do not differ significantly by Tukey s test. Regression analysis: Rate of SS (X) vs. grain yield (Y) = X X 2, R 2 = ; rate of yoorin (X) vs. grain yield (Y) = X X 2,R 2 = ; rate of arad (X) vs. grain yield (Y) = X X 2,R 2 = SS, simple superphosphate. Table 2 Relationship between shoot dry weight (X), number of pods per plant (X), and grain harvest index (X) and grain yield (Y) (values are averages of 3 years) Plant parameter Regression equation R 2 Shoot dry weight vs. grain yield Y = X Number of pods per plant vs. grain yield Y = X Grain harvest index vs. grain yield Y = X X , Significant at the 5% and 1% probability levels, respectively. the least number of grains per pod. Regression analysis of number of grains per pod versus P rate was not significant. Hence, these equations were not presented. One hundred grain weight was greater in the first year of soybean cultivation and decreased during second and third years of cultivation (Table 4). Regression analysis showed that 92% of the variation in the 100-grain weight was due to single supephosphate, 34% of the variation was due

6 2720 N. K. Fageria, A. Moreira, and C. Castro Table 3 Number of grains per pod of soybean as influenced by P source and rate P source and rate (kg ha 1 ) 1st year 2nd year 3rd year Average Control (without P) Simple superphosphate Yoorin Arad Simple superphosphate Yoorin Arad Simple superphosphate Yoorin Arad Average Ftest Year (Y) Prate(P) Y P CV (%) 7.9 Table 4 One hundred grain weight of soybean as influenced by P fertilization P source and rate (kg ha 1 ) 1st year 2nd year 3rd year Average Control (without P) Simple superphosphate Yoorin Arad Simple superphosphate Yoorin Arad Simple superphosphate Yoorin Arad Average Ftest Year (Y) Prate(P) Y P CV (%) 3.8, Significant at the 5% and 1% probability levels, respectively. Notes. Regression analyses were done with average values of 100-grain weight for each P source. Rate of SS (X) vs. 100-grain weight (Y) = X X 2,R 2 = Rate of yoorin (X) vs. 100-grain weight (Y) = X, R 2 = Rate of arad (X) vs. 100-grain weight (Y) = X, R 2 =

7 Phosphorus versus Soybean 2721 to Yoorin, and 72% of the variation was due to Arad. Fageria, Baligar, and Clark (2006) reported that adequate mineral nutrition including P is one of the important management practices to improve yield components in legume crops. Phosphorus Uptake and Use Efficiency Phosphorus uptake in grain was significantly influenced by P treatment (Table 5). However, influence of P treatment on P uptake in shoot was not significant. Phosphorus uptake in shoot varied from 1.84 to 2.32 kg ha 1, with an average value of 2.13 kg ha 1.In grain, P uptake varied from 11.2 to 14.8 kg ha 1, with an average value of 13.4 kg ha 1. This means that P uptake was greater in grain than in shoot. Greater uptake of P in soybean grain compared to shoot has been reported by Fageria, Baligar, and Clark (2006). Phosphorus accumulation in grain had a quadratic significant influence on grain yield (Y = X X 2,R 2 = ). This means that greater P uptake in grain was associated with greater grain yield in soybean. To produce 1 metric ton of soybean yield, 4 kg of P were accumulated in the soybean grains. Fageria, Baligar, and Jones (2011) reported that to produce 1 ton of soybean grain, 6 kg of P were accumulated in Brazilian Oxisol. Agronomic efficiency (kg grain / kg P applied) decreased with increasing P rate, except in Arad source of P (Table 6). In Arad also, agronomic efficiency was maximum at the lowest P rate. Greater agronomic efficiency at lower P rate indicates better P utilization by soybean at a low rate. These types of results are common in nutrient-efficiency studies in crop plants (Fageria 1992). Jarrell and Beverly (1981) reported that in any experiment with a nutritional variable, plants grown at the lowest nutrient concentrations would inevitably Table 5 Phosphorus uptake in the shoot and grain of soybean as influenced by P sources and rate (values are averages of the first 2 years) P source and rate (kg ha 1 ) P uptake in shoot (kg ha 1 ) P uptake in grain (kg ha 1 ) Control (without P) c Simple superphosphate abc Yoorin abc Arad bc Simple superphosphate ab Yoorin abc Arad bc Simple superphosphate a Yoorin ab Arad ab Average Ftest Prate(P) NS CV (%) , NS Significant at the 1% probability level and nonsignificant, respectively. Means followed by the same letter in the same column do not differ significantly at the 5% probability level by Tukey s test.

8 2722 N. K. Fageria, A. Moreira, and C. Castro Table 6 Phosphorus-use efficiency in soybean as influenced by P source and rate (values are averages of first- and second-year crops) P rate (kg ha 1 ) AE (kg kg 1 ) UE (kg kg 1 ) ARE(%) Simple superphosphate Average Yoorin Average Arad Average Notes. AE, agronomic efficiency; UE, utilization efficiency; and ARE, apparent recovery efficiency. have the greatest utilization quotient because of a dilution effect. Overall, P-utilization efficiency (kg grain plus straw / kg P accumulated in grain plus straw) was greatest in the Yoorin and least in Arad phosphate. Greater utilization efficiency in Yoorin may be associated with greater uptake of P in shoot and grain under this treatment compared to two other sources of P. Overall, apparent recovery efficiency of P was similar in superphosphate and Yoorin and was lower in Arad. The lower P recovery efficiency in Arad was due to low uptake in straw and grain compared to two other sources of P. Overall, P recovery efficiency was about 10% in three P sources of fertilization. This lower efficiency was associated with P immobilization by Fe and aluminum (Al) oxides in the Oxisol under investigation. Phosphorus recovery efficiency of less than 20% has been reported in Brazilian Oxisols by annual crops, including soybean (Fageria Baligar, and Clark 2006). Conclusions Phosphorus application significantly increased soybean grain yield in Brazilian Oxisol. Optimal P rate for maximum grain yield varied from 36 to 296 kg P ha 1 or 83 to 678 kg P 2 O 5 ha 1 depending on P source. Shoot dry weight, number of pods per plant, and grain harvest index was significantly associated with grain yield. However, maximum variation in grain yield was due to number of pods per plant. Phosphorus uptake in grain was about sixfold compared to P uptake in grain. Phosphorus uptake in grain had a highly significant association with grain yield. Overall, utilization and apparent recovery efficiency were greater in Yoorin compared to simple superphosphate and Arad sources of P fertilization. However, agronomic efficiency was greater in simple superphosphate compared to Yoorin

9 Phosphorus versus Soybean 2723 and Arad phosphates. In addition, simple supephosphate also contains S, which can be beneficial for the crop growth on S-deficient soils. References Bedin, I., A. E. Furtini Neto, A. V. Resende, V. Faquin, A. M. Tokura, and J. Z. L. Santos Phosphate fertilizers and soybean yield in soils with different phosphate buffer capacities. Revista Brasileira de Ciência do Solo 27: Cordeiro, D. S., D. Pottker, C. M. Borkert, G. J. Sfredo, A. N. Mesquita, R. C. Dittrich, and J. B. Palhano Production and economic yield of soybean as influenced by rate and source of phosphorus in the region of Dourados (MS). Revista Brasileira de Ciência do Solo 3: Embrapa (Empresa Brasileira de Pesquisa Agropecuaria) Manual of soil analysis methods, 2nd ed. Rio de Janeiro: National Soil Research Center. Fageria, N. K Maximizing crop yields. New York: Marcel Dekker. Fageria, N. K The use of nutrients in crop plants. Boca Raton, Fl.: CRC Press. Fageria, N. K., and V. C. Baligar Fertility management of tropical acid soils for sustainable crop production. In Handbook of soil acidity, ed. Z. Rengel, New York: Marcel Dekker. Fageria, N. K., and V. C. Baligar Ameliorating soil acidity of tropical Oxisols by liming for sustainable crop production. Advances in Agronomy 99: Fageria, N. K., V. C. Baligar, and R. B. Clark Physiology of crop production. NewYork: Haworth Press. Fageria, N. K., V. C. Baligar, and C. A. Jones Growth and mineral nutrition of field crops,3rd ed. Boca Raton, Fl.: CRC Press. Fageria, N. K., M. P. Barbosa Filho, L. F. Stone, and C. M. Guimarães Phosphorus nutrition in upland rice production. In Phosphorus in Brazilian agriculture, ed. T. Yamada and S. R. S. Abdalla, Piracicaba, Brazil: Brazilian Potassium and Phosphate Institute. Fageria, N. K., and F. Breseghello Nutritional diagnostic in upland rice production in some municipalities of State of Mato Grosso, Brazil. Journal of Plant Nutrition 27: Jarrell, W. M., and R. B. Beverly The dilution effect in plant nutrition studies. Advances in Agronomy 34: Oliveira, E. L., O. Muzilli, K. Igue, and M. T. T. Torneiro Evaluation of the agronomic efficiency of rock phosphates. Revista Brasileira de Ciência do Solo 8: Ramos, M. G Efficiency of eight phosphates for wheat and soybean on an argillaceous dark red latosol. Revista Brasileira de Ciência do Solo 6: Sfredo, G. J., E. Paludzysyn Filho, E. R. Gomes, and M. C. N. Oliveira Soybean responses to phosphorus fertilization and liming in a paleudult soil of Balsas, State of Maranhão, Brazil. Revista Brasileira de Ciência do Solo 20: