Estimación de biomasa y carbono orgánico del suelo en dos sistemas de producción bananero en la provincia el oro

Abstract

The two main problems affecting agricultural activities in the region are low water availability and low soil fertility, which limit the productivity of the main crops. Banana production in Ecuador is an intensive monoculture system that generates a large volume of permanent biomass that can be used for various agricultural activities, such as transformation into organic fertilizers, which increases organic matter, which in turn is a strategy for soil carbon sequestration. It is essential that these levels are maintained because a decrease in the volume of biomass in the soil will generate more CO2 emissions, which will have a decisive influence on climatic conditions. In order to counteract the release of greenhouse gas emissions, banana crop residues such as leaves, rachis and pseudostems are a source of biomass for carbon sequestration and a viable option for combustion and bioproducts. In Ecuador, approximately 20 tons of agricultural residual biomass are generated annually, which shows a great potential for soil preservation. This research was framed in the study of aerial and soil biomass, the study was conducted in the province of El Oro, the conventional farm "La Fortuna" is located in the city of Machala in the Puerto Grande sector, while the organic farm "San Pablo" is located in the canton of El Guabo, Tendales parish; regarding the comparison of C storage in two banana production systems (organic and conventional), to determine the storage in each of these. Soil samples were extracted (0-15 cm; 15-30 cm; 30-45 cm) to evaluate physical and chemical properties (Da, pH, MO, COS) and also to extract aerial biomass which was taken from harvested plants that were segregated into three components: foliage, pseudostem and corm, the in situ weight of these components was recorded and then taken to the laboratory for drying until reaching a constant weight. The ratio between fresh and dry weight of biomass was recorded. In addition, the circumference of the plants at 30 cm and 130 cm above the ground, the height of the pseudostem and the total height were measured, which were used to calculate the residual aboveground biomass. The analysis of the soil and plant biomass samples was carried out at the UTMACH Soil Laboratory. The bulk density was determined by the method of the cylinder of known volume (Forsythe-Warren et al., 1975), which establishes that the bulk density for both soil uses presents very close averages at different depths. In general, at the "La Fortuna" farm the average recorded for a depth of (0-15 cm) was 1.41 g/cm3, at (15-30 cm) with an average bulk density of 1.40 g/cm3 and at (15-30 cm) with an average bulk density of 1.40 g/cm3. 40 g/cm3 and at (30-45 cm) with a mean bulk density of 1.33 g/cm3, followed by the Organic farm "San Pablo" where (0-15 cm) with a mean bulk density of 1.37 g/cm3, at (15-30 cm) with a mean bulk density of 1.38 g/cm3and at (30-45 cm) with a mean bulk density of 1.29 g/cm3. The Walkley and Black (1934) method was used to determine the organic matter content and subsequently determine the C content present in the soil on the two study farms. Statistical analysis showed that there were no significant differences in the contents of COS and AGB (residual biomass), registering a slightly higher percentage for the organic farm "San Pablo" which presents a depth of (0-15 cm) with an average carbon percentage of 1.31%, at (15-30 cm) with an average carbon percentage of 0.89% and at (30-45 cm) with an average carbon percentage of 0.29%, followed by the organic farm "San Pablo" with a depth of (0-15 cm) with an average carbon percentage of 1.31%, at (15-30 cm) with an average carbon percentage of 0.89% and at (30-45 cm) with an average carbon percentage of 0.29%. 29 %, followed by the Conventional farm "La Fortuna" where samples were taken at different depths of (0-15 cm) with an average carbon percentage of 1.28 %, at (15-30 cm) with an average carbon percentage of 0.63 % and at (30-45 cm) with an average carbon percentage of 0. The data recorded for AGB are the Conventional farm "La Fortuna" with an average of 24.38 % reached the maximum value of AGB, followed closely by the Organic farm "San Pablo" which presented the lowest value of AGB with an average of 23.07 %.