The Republic of Moldova is situated in a geographic zone with extremely favorable climate and very fertile soil. This combination giver an enormous opportunity for the agricultural sector of the national economy that allows and achieve rich and high quality harvest avoid intensive application of non-organic chemicals and fertilizers. In this connection to obtain the high quality and cleaner products one role important has on organic agriculture. However organic agriculture has a major contribution to lasting economic development and also plays an important role to improving the condition of the environment, water quality and biodiversity.
The practice of many farmers demonstrated that switching from conventional agriculture to organic farming is not easy, because as a result of this conversion farmers may have losses. For reduce these losses it is necessary to make a slow transition to production of organic agriculture. According to the basic methods and principles of organic agriculture, uses of fertilizers and other soil improvers, pesticides, growth promoters, etc. is not allowed. Taking into consideration those mentioned during the conversion period an important role can be play the leguminous crops and perennial herbs. More several crops species a making the subject of this desideratum. This group includes the following crops: pea, bean, soybean, lentil, chickpea, broad bean, peanut, and from perennial herbs: alfalfa, sainfoin. The agro-climatic conditions of the Republic of Moldova are favorable for cultivation and expansion of the leguminous crops areas. The leguminous crops with helping of the rhizobia bacteria, which come in symbiosis with plants, they can transformation of atmospheric nitrogen in molecular nitrogen which it into an accessible form for plants. For example, on 1 ha soybean area can be accumulate about 100 kg. of nitrogen in year. The alfalfa crop can accumulate in average of 150-160 kg per ha of biological nitrogen, which is equivalent to 500 kg of ammonium nitrate. At the same time, it is necessary to mentioned that nitrogen, which is fixed by the rhizobia bacteria, is used for a longer period, comparative with nitrogen which used by the mineral fertilizers: 51% in the first year, 27% in the second and 22% three year for crops, which are sown after the leguminous crops for grains. The researcher Bob Rodale from Rodale Institute, Pennsylvania State, USA has been demonstrated that converting conventional farming to organic need to pass with leguminous crops. According by data the yield of maize which was obtained at the third year, after two years, where was sown leguminous crops, was higher compared with yield, where was used mineral fertilizers and pesticides.
Analyzing the compartment of the structure of leguminous crops in Moldova we can mention the following: if about two decades ago the share of leguminous crops and perennial herbs in the structure of field crops constituted 8-12%, including 180-220 thousand ha of alfalfa and 80-100 thousand ha of pea, then in recent years the structure of the land sown with perennial herbs, especially alfalfa, has changed essentially. The area of perennial herbs decreased from 180-200 thousand ha to 30-35 thousand ha. The percentage of pea in structure of field crops declined 4-5 times. Currently the share of leguminous crops and perennial herbs (alfalfa, sainfoin), is about only 6 percent, including leguminous crops – only 4 percent. The countries with the advanced agriculture the share of perennial herbs (alfalfa, sainfoin) and leguminous crops is 20-30%. The share of leguminous crops for the pedo-climatic conditions of our country, should be 20-25 percent, including 10-13% of the alfalfa.
Thus, the increase of the leguminous crops areas can lead not only to breaking the chain of diseases and weeds, but also to diminish of the harvest losses by agricultural producers in the transition period from conventional agriculture to organic farming. The harmonious combination at the leguminous crops with the livestock sector and the processing industry can lead to create sustainable, environmentally friendly and with high-yield farming.