**Mineral Nutrition**

Vlado Kovacevic1, Aleksandra Sudaric2 and Manda Antunovic1 *1University J. J. Strossmayer in Osijek, Faculty of Agriculture 2Agricultural Institute Osijek Croatia*

#### **1. Introduction**

388 Soybean Physiology and Biochemistry

Giancola, S., Salvador, L., Covacevich, M., Iturrioz, G. (2010). Análisis de la cadena de soja

Ghida Daza, C. (2002). Alternativas para el almacenaje. Silo bolsa de grano seco. In: *Maíz, actualización 2002*. Información para extensionistas. INTA Marcos Juárez. Gutman, G., Lavarello, P. (2003). La trama de oleaginosas en Argentina. In: *Estudios sobre el* 

Instituto Nacional de Estadística y Censos (INDEC). (2009). Estadísticas macroeconómicas.

Instituto Nacional de Tecnología Agropecuaria (INTA). Consejo del Centro Regional Santa

Lopez, G., (2008). *Vamos al grano?. El Rol del Estado en el comercio granario argentino* (primera

Nardi, M., Davis, T., (2006). Supply chain management in Argentina and Brazil and the

Obschatko, E., (1997). *Articulación productiva a partir de los recursos naturales. El caso del* 

CEPAL, Buenos Aires. UNDP Project RLA 88/039. Buenos Aires, Argentina. Oficina Nacional de Control Comercial Agropecuario (ONCCA). 2006. Existencia física de

Quaim, M., Traxler, G. (2002). Roundup Ready Soybeans in Argentina: Farm Level,

SAGPyA (2007). Informe de fletes y preliminar de transporte de granos. 12/02/2011.

Schavarzer, J., Tavosnanska, A. (2007). *El complejo sojero argentino. Evolución y perspectivas*.

Tavarez, C. (2004). Factores críticos a Competitividade da Soja no Parana e no Mato Grosso.

Trigo, E., Cap, E. (2006). *Diez años de cultivos genéticamente modificados en la Agricultura* 

United State Department of Agriculture (USDA). (2010). USDA data base: commodities and

Available from: http://www.minagri.gob.ar/publicaciones.php

Companhia Nacional de Abastecimiento. Brasilia. 9 pp.

www.fas.usda.gov/commodities.asp and /trade.asp

Biotecnología- ARGENBIO, Buenos Aires, Argentina. 53 pp

*Agroindustriales Nº 3.* INTA, Buenos Aires. ISSN 1852-4605.

*Tramas B-3*. Bisang R., y G. Gutman. CEPAL-ONU, Buenos Aires.

2011. http:/www.inta.gov.ar/reconquista/crsantafe/docsoja.htm

edición). Editorial Cúspide. ISBN 9789870588023. (288 pp).

granos al 31 de Diciembre 2006. 6/02/2011. Available from:

*companies.* Buenos Aires, March 2006. 92 pp.

http://www.onnca.gov.ar

Buenos Aires.

Ravello, Italia. Julio 2002.

20/02/2011. Available from: http://www.indec.mecon.gov.ar

en la Argentina. En: *Estudios Socioeconómicos de los Sistemas Agroalimentarios y* 

*sector Agroalimentario. Estudio 1.EG.33.7 Componente B: Redes Agroalimentarias,* 

Fe., (2009). Documento institucional. El avance de la soja en la Argentina y la sostenibilidad de los sistemas agrícolas. In: *INTA Centro Regional Santa Fe*. Febrero

Effect on World Agricultural Competitiveness. *Presentation given to trading* 

*complejo oleaginoso argentino* (Primera edición). Documento de trabajo Nº 74.

Environmental and Welfare Effects. *Proceedings of Conference ICABR on Agricultural Biotechnologies: New Avenues for Production, Consumption and Technology Transfer*.

Centro de Estudios y Perspectivas de la Argentina (CESPA). Universidad de Buenos Aires. Facultad de Ciencias Económicas. Documento de trabajo Nº 10.

*Argentina*. Consejo Argentino para la Información y el Desarrollo de la

trade. In: USDA Foreign Agricultural Service. 29/01/2011. Available from:

Sixteen nutrient elements are essential for the growth and reproduction of plants. The source of carbon (C) and oxygen (O) is air, while water is source of hydrogen (H). Ninetyfour percent or more of dry plant tissue is made up of C, H and O. Remaining thirteen elements, represent less than 6 percent of dry matter, are often divided in three groups (Johnson, 1987). The primary nutrients are nitrogen (N), phosphorus (P), and potassium (K). Secondary nutrients are sulfur (S), calcium (Ca) and magnesium (Mg). Micronutrients are required by the plant in very small amounts. They are iron (Fe), manganese (Mn), boron (B), zinc (Zn), copper (Cu), molybdenum (Mo) and chlorine (Cl). Nutrient removal of soybean by tone of grain and correspondingly biomass are about 100 kg N, from 23 to 27 kg P2O5, from 50 to 60 kg K2O, from 13 to 15 kg CaO, from 13 to 16 kg MgO and considerable lower amounts of the other nutrients. In general, the fertilizer requirements for soybean are typically less than for other crops such as maize and wheat. Bergmann (1992) reported adequate concentrations of nutrients in dry matter of fully developed leaves at the top plant without petioles at the end of blossom as follows: 4.50-5.0 % N, 0.35-0.60 % P, 2.5-3.70 % K, 0.60-1.50 % Ca, 0.30-0.70 % Mg, 25-60 ppm Zn, 30-100 ppm Mn, 25-60 ppm B, 10-20 ppm Cu and 0.5-1.0 % Mo.

#### **2. Nitrogen**

Symbiotic nitrogen (N) fixation had important role in supplying of leguminose plants including soybean, by N. It is estimated that by this source is possible to bind from 40 to 300 kg N/ha/year (Bethlenfalvay et al., 1990). Field studies by Bezdicek et al (1978) showed that soybeans are capable of fixing over 300 kg N/ha when the soil is low in available N and effective strains of *Bradyrhizobia* are supplied in high number. Also, part of leguminose needs for N is settled by its uptake in mineral forms, mainly in NO3 - and NH4+ forms. Soybean contains in mean from 1.5 to 1.6 % and from 6.5 to 7.0 % N in dry matter of aboveground part and grain, respectively (Hrustic et al., 1998). N amounts removal from soil by soybean depending on numerous external and internal factors. For forming of 1 t of grain and correspondingly vegetative mass of soybean is needed about 100 kg N.

Worldwide some 40 to 60 million metric tons (Mt) of N2 are fixed by agriculturally important legumes annually, with another 3 to 5 million Mt fixed by legumes in natural ecosystems, providing nearly half of all the nitrogen used in agriculture (Hungria & Campo, 2004). Therefore, biological dinitrogen fixation by leguminous plants is a significant source of available nitrogen in both natural and managed ecosystems (Galloway et al., 1995) that contributes to soil fertility and replaces the use of synthetic nitrogen fertilizer.

The host plant provides carbon substrate as a source of energy, and bacteria reduce atmospheric N2 to NH3 which is exported to plant tissues for eventual protein synthesis (Vincent, 1980). Nitrogen fixation occurs in different intensities in soil, during which the energy of plant assimilates is used, and because of this, bacterial activity forms unbreakable relationship with plants. The proportion of nitrogen derived from fixation varies substantially from zero to as high as 97%, and most estimates fall between 25% to 75% (Deibert et al., 1979; Keyser & Li, 1992, Russelle & Birr, 2004).

N is mobile in plants and it is quickly translocate from old to young organs. For this reason, symptoms of N deficiency (first lightgreen and later greenyellow colours of leaves) obtain on the older leaves. In the more over stages it is found falling off the flowers and pods (Vrataric & Sudaric, 2008). Excess of N had unfavorable impacts on soybean productivity, mainly due to susceptibility to diseases, low temperatures and drought. Symptoms of N oversupplies are increasing of height of plants, longer internodies and lodging incidences. Soybean is the most susceptible leguminose to nitrate oversupplies. Under these conditions inhibition of nodule forming and nitrogenase activities were found Harper & Gipson, (1984). Also, high nitrate in apoplast of soybean had effect on pH increasing, immobilization of iron and developing of iron chlorosis in soybean (Hrustic et al., 1998).

N supplies of soybean could be estimated by number and activities of bacterial nodules of genus *Rhisobium* and *Bradyrhisobium*, contents of total and mineral N in oil, nitratreductase activities etc. Inadequate N supplies are possible to correct by mineral fertilization. Activities of bacteria are reduced under good supplies of soil by N (as results either high N fertilization or favorable conditions for organic matter mineralization) and acid soil pH.

Recommendations for soybean fertilization are depended on soil test results and planned yields. Under conditions of the northern Croatia N recommended quantities are mainly in range from 60 to 90 kg N/ha mainly in spring. Using of N as urea in autumn over 100 kg/ha resulted by absence of nodule bacteria or minimizing their amounts (Vrataric & Sudaric, 2008). By testing 12 localities in fertile soils (chernozem and similar soil types) of Vojvodina (Serbia) was found that inoculation had considerable more impacts on yields of soybean compared to N fertilization and that using 90 kg N/ha was not found nodule on soybean root (Belic et al., 1987; Relic 1988 – cit Vrataric & Sudaric, 2008). Based on experiences from very fertile soils in Ohio (Johnson, 1987), soybean is not recommend for N fertilization in case of sufficient amounts of N-fixing bacteria and only in first growing of soybean on individual soil recommendation is applying 45 kg N/ha. Also, in Illinois mineral N fertilization had not effects on soybean yields even in cases of band fertilization close to soybean rows. Also, N fertilization was superfluous for maize in soybean-maize rotation (Welch et al., 1973). However, the experiences from USA are not possible to applying in less fertile soils of middle and eastern Europe.

Soil acidity is often limiting factor of the symbiotic nitrogen fixation process. Soils with low pH values lack calcium, and have surplus of toxic aluminium, so that soybean roots in acidic soils don't have mucous coating on surface which purpose is to dissolve root pectines, enables root hair curling and root hair penetration by bacteria. This is very important during the first few days after inoculation that is after sowing inoculated seed. Therefore, soils with pH value less than 5.5 (acidic soils) are not suitable for soybean growing, because they lack necessary conditions for development of useful bacteria whose growth is slowed down or

of available nitrogen in both natural and managed ecosystems (Galloway et al., 1995) that

The host plant provides carbon substrate as a source of energy, and bacteria reduce atmospheric N2 to NH3 which is exported to plant tissues for eventual protein synthesis (Vincent, 1980). Nitrogen fixation occurs in different intensities in soil, during which the energy of plant assimilates is used, and because of this, bacterial activity forms unbreakable relationship with plants. The proportion of nitrogen derived from fixation varies substantially from zero to as high as 97%, and most estimates fall between 25% to 75%

N is mobile in plants and it is quickly translocate from old to young organs. For this reason, symptoms of N deficiency (first lightgreen and later greenyellow colours of leaves) obtain on the older leaves. In the more over stages it is found falling off the flowers and pods (Vrataric & Sudaric, 2008). Excess of N had unfavorable impacts on soybean productivity, mainly due to susceptibility to diseases, low temperatures and drought. Symptoms of N oversupplies are increasing of height of plants, longer internodies and lodging incidences. Soybean is the most susceptible leguminose to nitrate oversupplies. Under these conditions inhibition of nodule forming and nitrogenase activities were found Harper & Gipson, (1984). Also, high nitrate in apoplast of soybean had effect on pH increasing, immobilization of iron and developing of iron chlorosis in

N supplies of soybean could be estimated by number and activities of bacterial nodules of genus *Rhisobium* and *Bradyrhisobium*, contents of total and mineral N in oil, nitratreductase activities etc. Inadequate N supplies are possible to correct by mineral fertilization. Activities of bacteria are reduced under good supplies of soil by N (as results either high N fertilization or favorable conditions for organic matter mineralization) and acid soil pH. Recommendations for soybean fertilization are depended on soil test results and planned yields. Under conditions of the northern Croatia N recommended quantities are mainly in range from 60 to 90 kg N/ha mainly in spring. Using of N as urea in autumn over 100 kg/ha resulted by absence of nodule bacteria or minimizing their amounts (Vrataric & Sudaric, 2008). By testing 12 localities in fertile soils (chernozem and similar soil types) of Vojvodina (Serbia) was found that inoculation had considerable more impacts on yields of soybean compared to N fertilization and that using 90 kg N/ha was not found nodule on soybean root (Belic et al., 1987; Relic 1988 – cit Vrataric & Sudaric, 2008). Based on experiences from very fertile soils in Ohio (Johnson, 1987), soybean is not recommend for N fertilization in case of sufficient amounts of N-fixing bacteria and only in first growing of soybean on individual soil recommendation is applying 45 kg N/ha. Also, in Illinois mineral N fertilization had not effects on soybean yields even in cases of band fertilization close to soybean rows. Also, N fertilization was superfluous for maize in soybean-maize rotation (Welch et al., 1973). However, the experiences from USA are not possible to

Soil acidity is often limiting factor of the symbiotic nitrogen fixation process. Soils with low pH values lack calcium, and have surplus of toxic aluminium, so that soybean roots in acidic soils don't have mucous coating on surface which purpose is to dissolve root pectines, enables root hair curling and root hair penetration by bacteria. This is very important during the first few days after inoculation that is after sowing inoculated seed. Therefore, soils with pH value less than 5.5 (acidic soils) are not suitable for soybean growing, because they lack necessary conditions for development of useful bacteria whose growth is slowed down or

contributes to soil fertility and replaces the use of synthetic nitrogen fertilizer.

(Deibert et al., 1979; Keyser & Li, 1992, Russelle & Birr, 2004).

applying in less fertile soils of middle and eastern Europe.

soybean (Hrustic et al., 1998).

completely enabled. Strains found on soybean roots in this type of soils are mostly ineffective, and when cut in half are green in colour. Situation is completely opposite in fertile neutral or mildly alkaline soils like chernozem. In these types of soil nitrogen fixing bacteria have not only good conditions for development, but also they can survive in large numbers for many years after soybean was grown. In such soils it is not necessary to perform seed bacterisation if soybean is in rotation every four years.

In case of low effects of inoculation on nodule bacteria development it is recommend topdressing with 50 kg N/ha in form of calcium ammonium nitrate (27% N) in term close to flowering or at beginning of flowering (Vrataric & Sudaric, 2008).

Organic manures cannot alone meet the heavy demands of nutrients in intensive soybean production because of their limited availability and restricted nutrient supply. A complementary use of organic manures and mineral fertilizers may meet the goal of adequate and balanced supply of required nutrients to crops. The soybean grain yield with recommended NPK fertilization and 25 kg N/ha + 1 t neem cake/ha combinations was significantly more than the other only chemical and organic source of nutrition (Table 1).

Soybean grain quality (crude protein and oil contents) and grain yield as affected by fertilization (in. = inoculated; neem cake = n.c.; FYM = farm-yard manure 5 t/ha; NPK 20:60:40 = recommended NPK-fertilization)


Table 1. Effects of inorganic and organic sources of nutrients on grain quality and yield of soybean (Saxena et al., 2001)
