Irrigation and Food Security: Case of Soybean Production in Serbia

Introduction

Soybean is a legume, which belongs to the group of thermophilic plants, with wide area of spreading (natural habitat). Its vegetation varies, and it can last from 100 to 145 days. Depending on the variety used, it requires temperature sum from 1,600°C to 3,200°C (Miladinović, Hrustić, & Vidić, 2011). This is one of the oldest plants on the Earth. It originates from Asia (specifically, from China – Manchuria region), from where it was spread to the East and Southeast Asia (Korea, Japan, Vietnam, Indonesia, and India), and then to other continents. Its presence in America was firstly recorded in 1804. As an arable crop, it began to be cultivated in Europe in the XIX century, while in Serbia it was introduced at the beginning of the XX century. Globally, its intensive production intensified just before the World War II. Optimal areas for its growing are between 56° north and 45° south latitude (Stamenković, Bošnjak, & Stamenković, 2007).

The specific chemical composition of soybean (it is the only plant which contains all essential amino acids necessary for the functioning of the human body) ranks it among the most important crops (oilseeds) intended for human and animal nutrition. According to its usability, soybean proteins are equivalent to the proteins of animal origin. For that reason, it can be used for proteins synthesis in the human body. It also contains vitamins, especially thiamine, riboflavin, vitamin B6, niacin, and to some extent vitamins C, D, E, and K, as well as folic and pantothenic acid. The grain also contains substantial amount of microelements such as calcium, phosphorus, potassium, iron, sulphur, manganese, sodium, molybdenum, copper, boron, iodine, cobalt, and zinc, as well as around 18% of oil that contains almost 85% of unsaturated fatty acids (Roljević, Subić, & Jeločnik, 2009).

Diversification of it potential use (food and feed industries, pharmaceuticals and cosmetics, up to the production of biodiesel) has resulted in the growing demand and expansion of the harvested areas under the soybean. In human nutrition (adequate substitute for meat), it is usually used in the form of seed, bleached germ, or soybean oil. It increases the overall nutritional and biological value of some food products, and it is directly used in alimentation as soybean steaks, milk, cheese, pate, or flour. Contemporary medicine recommends soybeans as a foodstuff that prevents the occurrence of cardiovascular diseases and cancer, as well as for regulation of digestion and maintaining of hormonal balance.

Soybean is an essential component for animal feeding. It can be a part of concentrated mixtures (usually as soybean meal or some other waste obtained during the industrial processing of soybean, rich in proteins and minerals), or used as voluminous (bulky) feed (use of vegetative organs – stem and leaves). Besides all, soybean has a large agro-technical importance, as it favorably affects the maintaining and improvement of soil structure with its well-developed and deep root system. Also, in symbiosis with specific bacteria (nitrogen fixers), after meeting its own need in nitrogen, it enriches the topsoil layer with above-mentioned microelement. That is why soybean is highly recommended preceding crop in the crop rotation for many plant species, especially for cereals (Đorđević & Nenadić, 1980).