Evolution of Soil-Crop System after Three Year of Aplication the Pig Slurry with Fertilizer Organic in Crop of Broccoli.
Miriam Llona Sr. and Ángel Faz II. Univ Politecnica de Cartagena, Paseo Alfonso XII, 48, Cartagena, Spain
That the pig slurry at the moment constitutes a serious half environmental problem it owes himself mainly to the change in the system of swine exploitation, bound to their intensivity. Among the years 60 and 90, in Spain, there was a reduction of the exploitations of pig with soil of 75% (Coll, 1993). This tendency to a productive system of intensive type with exploitations without soil, high mechanization, feeding with feed, etc. of consequences, the most important consists in that the produced slurry doesn't have a territorial area where they can be applied or poured, also the specialization of some areas that to make of the pig productions, an almost exclusive production increases this problem. Diverse studies, coincide in affirming that the most effective and economic method of confronting the problem of the accumulation of the waste of organic type coming from the intensive swine raising, is through its application in the soil. The production of pig in Spain is on the 22 million heads. This production concentrates for the most part on 10 Autonomous Communities, being the Region of Murcia the fifth with near the 2 million heads and the second after Cataluña in number of heads for surface. Inside the Region of Murcia the Municipality of Lorca is the one that possesses a bigger number of exploitations with 2657 (43%), ending up taking place near the 4 million pig slurry m3 a year (M.A.P.Y.A, 2000). The objective of this work was to determine the effects of application of pig slurry to the results of the three year application of pig slurry for broccoli crop, especially the contribution of total organic carbon, N, P, K and heavy metals to the system soil-crop. The main interest is to find out the optimum amount of this residue that can be added to the soil as an organic fertiliser. The study will enable to determine the potential agronomic use of pig residues, which is a high-priority issue for the Guadalentin Valley.The study was carried out in the alluvial plain of Guadalentin Valley (Lorca, Murcia, southern Spain). The soils developed in this area are classified as Calcaric Fluvisols (FAO-ISRIC-ISSS, 1998). The experiment is planned to be for 3 years, using broccoli. Plots have been selected each one with 10 x10 m2 using different treatment of pig slurry: blank, B (4,86 L m2), C (11,05 L m2) and D (14,86 m2); residual (R) and accumulative (A) effects are considered. The highest dose was considered extremely high for the local EC norms. However, this will contribute to the knowledge regarding the potential negative consequences of pig slurry application in the area. The soil is higher in pH, N, P, K and organic carbon in effect accumulative. Cu and Zn, in general increase, however, these contents are not above those established by law. In the crop, the content of nitrate is influenced by PS after 3 years of experiment. These contents are below those established by law. The crop in leaf analysis presents a notorious increase in the content of NO3- as you increases in the slurry treatment, being bigger the accumulative effect, however these values don't surpass that specified by the law. N, P, K, Cu and Zn also present an increase, arriving at normal levels. The influence of the PS on soil chemical characteristics and on production is less notorious in experiences.