SOIL FERTILITY

Author: BONELLI BACCHI CESAR LUIS.
Year: 2003.
University: POLITÉCNICA DE MADRID.
Place of defense: ESTI MONTES.
Place of preparation: ESTI MONTES.

Summary: In the central region of the province of Santiago del Estero has carried out an intensive logging in recent years, causing forests demean units of low-value forest. On the other hand, livestock activities resulted not only degredación natural grassland by overgrazing, but prevented the natural regeneration of valuable forest species. Because of wet conditions and the presence of soils derived from sedimientos lesicos, with a high productive potential, the area is under heavy farming activity. As you know, the soil is a dynamic natural system that plays an important role in the ecosystem, so changes or alterations in the system and the functionality of the ground. The overall objective of this study is to characterize the physical parameters that determine the quality of soil in terms of use over time to identify degradation processes and provide guidelines for the management of soil conservation. A field survey and laboratory were established indicators of soil quality. The results clearly show that the soil organic carbon decreases with clearing and subsequent use of the land for agriculture. One of the most direct consequences is the loss of the stability of soil aggregates, creating an imbalance that affects the porous system of agricultural soils, with a decrease of the total porosity. The analysis of the distribution of different pore sizes indicates that the percentage of macroporos, for the storage of air and the movement of water into the interior of the soil, is significantly lower in soils subjected to agricultural practices, while the mesoporos , for the storage of water, is significantly higher. The values of hydraulic conductivity indicate that the decline in macroporos in agricultural soils, affects a decline in the rate of water infiltration.

Author: BRAVO MEDINA CARLOS ALFREDO.
Year: 2004.
University: CÓRDOBA.
Place of defense: E.T.S.I. AGRONOMOS Y MONTES.
Place of preparation: E.T.S.I. AGRONOMOS Y MONTES.

Summary: The overall aim of the thesis was to determine the influence of soil factors in the production plant considering different agricultural systems in southern Spain. To that end, we used different statistical tools, geoestadisticas and remote sensing that allowed: a) analyze the influence of tillage and traditional tillage on soil properties on the performance of peas and some biometric components associated with the cultivation, b) setting the parameters of soil with the greatest impact on performance and characterize management systems on the base.de parameters and soil cultivation c) to characterize the spatial variability of the physico-chemical properties of soil and yield of crops (peas, cotton) in two agricultural areas representative of the Andalusian countryside and finally, d) integrate information from a number of soil, vegetation index maps and yield of cotton to obtain homogeneous management zones in the context of precision agriculture. From the results it can be pointed out that after 22 years the land under tillage methods contrasting the Direct Seeding (OS) Laboreo Traditional (LT), presents some significant differences in soil factors related to soil fertility and the crop yield. The greatest impact surface of direct seeding is manifested mainly in improving the content of organic carbon, phosphorus and potassium available land, which means a better quality of soil from the point of view of agriculture and the environment. The direct seeding while maintaining production levels similar and sometimes greater than the traditional system, improving fertility, will make it possible to reduce the dose of potassium fertilization fosforada and preventing pollution and reducing production costs. The implementation of a series of statistical tools such as regression analysis and principal components for handling system was used to identify variables greatest impact on the performance of the pea crop, including the concentration of organic carbon, magnesium, calcium, phosphorus , biomass jopo and biomass pea. In addition, group allowed those variables that best characterize each of the evaluated tillage methods, resulting in the LT: incidence of jopo, biomass pea ca, Ca, Mg, CIC, and for direct seeding: P AC and biomasadel pea. The study of the distribution of fractions of phosphorus in this soil provides very valuable information about the influence of different management techniques on their dynamics and availability, with important implications for the management of fertilization fosforada. The application of direct seeding in the long run has resulted in increased accumulation surface of the labile fraction active representadapor P-CB, P-CDB, P-HCL, Po, which suggests that this treatment there is a greater availability of reserve and P that potentially can be used for cultivation. Regardless of the treatment of tilling the phosphate concentration in the soil is controlled by the solubility of calcium phosphate (P-Ca), which is related to the parent material of this land and accounts for 80% of the total phosphorus removal. However, the increase in the concentration of P-orgánico (Po), associated with a greater% of organic matter in direct seeding, it is interesting to consider, since improvement in the reserve P in the soil, when compared with the traditional system. The soil tillage handled with the least amount of phosphorus required to maintain adequate concentrations in l 8 to soluti 303 n soil to supply the needs of the crop compared with the ground handled with the traditional method.

Author: VILLA BERMEJO JESÚS EDUARDO.
Year: 2004.
University: LEÓN.
Place of defense: ESCUELA SUPERIOR Y TÉCNICA DE INGENIERÍA AGRARIA.
Place of preparation: ESCUELA SUPERIOR Y TÉCNICA DE INGENIERÍA AGRARARIA.

Summary: The work has been the comparison on the production of rye, barley and pasture has been implementing a dose of 6000 kg / ha of CaCO3 pure, in the form of foams azucarería, limestone, gypsum and dolomite, as well as its effect the different ways of Al present in the soil in some soils strategy acids located at raña of Camposagrado. Rioseco of Tapia (Leon).

Author: GARCIA NOVELO JORGE MARCELINO.
Year: 2005.
University: CÓRDOBA.
Place of defense: E.T.S.I. AGRONOMOS Y MONTES.
Place of preparation: E.T.S.I. AGRONOMOS Y MONTES.

Summary: Nitrogen is one of the most important elements in the olive grove, for his involvement in the vegetative growth, flowering, fruit-set and ripening fruit and production. As one of the most macronutrients used in the olive grove and has traditionally formed the basis of fertilization. The overall objective was to determine the effect of the dose and manner of implementation of N in agronomic parameters such as growth, fruit size, production, yield and quality of the fatty oil among others. They also studied the influence on the evolution of residual N in the soil, mineralization and losses by washing nitrates. In order to know the balance of nitrogen in the olive grove. It was established to two plots: on the farm "La Mina" Cabra and the station "Sale del Llano" Mengíbar. The treatments consisted of urea applications exclusively to the ground or combined application to soil applications of urea through leaf (50% - 50%) at doses of 0.0125, 0.25, 0.5 and 1 kg of N.árbol- 1 and year. After 10 years of study noted that the annual contributions of urea not increased production and growth of the tree. The application form ground + leaf (50% - 50%) contributed to a more efficient use of N. Senior N content in the fruit as a result of applications with high doses of N (1 kg N / tree) affected the quality of olive oil, reducing the content of polyphenols, bitterness and stability. It also increased the content of tocopherol. The annual contributions of urea increased the content of mineral N in the soil, mainly due to an increase in the nitrate content. The total N content was not significantly increased by the annual contributions of N. Increasing the dose of N reduces the efficiency of use of N and contributing to the increased losses from washing nitrates. The balance of N in the olive grove, suggested that trees without paying the process of N mineralization can contribute significantly at the entrance of N system suelo-planta. By contrast entries for the application of N fertilizer to trees, originates exits N system suelo-planta producing losses during n processes volatiliación, denitrification, immobilization and washing nitrates.

Author: YAGÒE CARRASCO MARÍA ROSA.
Year: 2005.
University: LLEIDA.
Place of defense: ESCUELA TÉCNICA SUPERIOR DE INGENIERIA AGRARIA.
Place of preparation: ESCUELA TÉCNICA SUPERIOR DE INGENIERÍA AGRARIA.

Summary: This paper aims to contribute to improving standards of a proper handling of slurry in the irrigation of Ebro Basin. First they have been evaluated different methods of determination of nitrogen content of slurry (Chapter 3), showing good results in the determination of the ammonia N slurry method Quantofix and electrical conductivity at dilution 1:10. We also compared two methods of application of slurry field (Chapter 4): the method of choice and the method of incorporador. Both the efficiency and uniformity of application were significantly higher in the method of application compared to the method of range, in a sampling of ammonia N content in soil 4 days after application. The effect of different treatments combined ore slurry and paid on money nitrate was evaluated in a trial in lysimeters drainage (chapter 5). Also at the conditions under which the trial took place, 75% of the losses of nitrate in a crop of corn in irrigated, occurring in the culture period, which highlights the importance of managing irrigation to control these losses . Finally attempted to quantify the residual effect of pig slurry (Chapter 6) applied in a maize crop spraying, but weather conditions prevented be realized quantification for years. After four years of implementation annual fund slurry in a maize crop was detected a significant residual effect on grain yield in a crop of barley later, but this effect was independent of the dose applied slurry. After the barley was planted a crop of corn observed that the residual effect was maintained and was also affected by the treatments applied the previous four years. It was also found that in sprinkler irrigation, the residual effect of pig slurry is important first years after its implementation but little relevant from the second year on the conditions under which the test was developed. In all tests, the pig slurry introduced the same capacity fertilizer that mineral fertilizers with the added value of its residual effect. The results indicate that the best option to fertilize corn in irrigated conditions in which they carried out tests of this project, are an application of slurry in cancels fund dose bajas-medias 30 t ha-1, supplemented by covering mineral fertilizer adequate performance expected of the crop.