Calidad de suelo en el cultivo de banano: evaluación, desafíos y oportunidades

Pesticide use in banana and plantain production and risk perception among local actors in Talamanca, Costa Rica

The book entitled Soil and Water Quality: An Agenda for Agriculture by the U.S. National Academy of Sciences caused people to ask whether soil quality assessments could be used to evaluate the impact of public policies such as the Conservation Reserve Program (CRP). However, differences in scale, perception of soil quality, and the inability to directly measure soil quality led to significant uncertainty among several potential users. A major challenge was determining how to evaluate and combine information from different indicators to make an overall soil quality assessment that is meaningful. Our objectives are to present a structured approach for interpreting soil quality indicator data and to introduce a conceptual framework that can be used to link the various scales of evaluation, including those needed for assessing effectiveness of public policies such as the CRP. The framework and its use are discussed and demonstrated using soil quality indicator data from published and unpublished studies. On-farm measurements suggest that biological indicators such as microbial biomass and respiration were affected most quickly and to the greatest extent when cultivated land was converted to grassland. Applying the conceptual framework to this data suggests that enrolling fragile lands into CRP had a positive soil quality effect. It also indicates that using no-till practices to return CRP land to row-crop production will preserve soil quality benefits of the CRP, but tilling to prepare a seedbed will destroy the benefits almost immediately.

Chapter 1 Concepts of soil quality and their significance

Ex-ante sustainability assessment of cleaner banana production systems

The objective of this study was to characterize the banana production systems and to identify the constraints it faces. A questionnaire survey and field observations were carried out with banana producers. At the end of the surveys, three main banana production systems were found: Monoculture (10%), banana-food crops intercropping (7%) and agroforestry (83%). In addition, four types of banana (cooking banana, plantain, beer banana and dessert banana) are integrated into banana cultivation systems, with a varying planting density depending on the type of cultural association envisaged. On average, a banana farmer owns 140 banana plants or stools on an average area of 0.68 ha, ranging from 0.0625 to 2 ha. On average, banana grower’s harvest 6 bunches per week with an estimated average weight of 12, 8.5 and 5.2 kg for plantain, cooking bananas and dessert banana, respectively. The weight estimate and marketing data for beer banana were not provided as it has not been sold in the market like other cultivars since the advent of BXW. The cultivation of bananas in Beni territory is constrained by diseases, mainly bacterial wilt of bananas (80%) and Banana Bunchy Top Disease (7%); climatic hazards (winds, drought and hail), insecurity, soil infertility, use of low-quality planting materials, inadequate agricultural practices, non-use of agricultural inputs, lack of technical and financial assistance as well as the weak involvement of state authorities in production. These constraints not only exacerbate the misery of banana producers but also contribute to the erosion of certain varieties and to the loss of the region's hegemony in banana production. In order to eradicate these threats, it is therefore essential to practice intensive cultivation with more inputs and especially improved cultivars. Key words: Constraints, cropping system, banana, Beni.

Soil quality not only depends just on the physical and chemical properties, but also on its biological properties. Biological processes provide soil, the resistance, resilience and buffering capacity to ameliorate stress. Soil biota is intrinsically related to the labile fraction of soil organic matter (SOM) involved in energy and nutrient cycling. Several authors over the years have reported that the more dynamic soil parameters such as microbial biomass, soil enzyme activity and soil respiration are more sensitive to changes in crop management practices and land use systems than SOM. Soil respiration is a well-established indicator to monitor decomposition, but is highly variable and can show wide natural fluctuations depending on substrate availability, moisture and temperature. Enzymes are important soil components involved in the soil nutrient dynamics. Enzyme activity in the soil system is considered to be a major contributor of soil microbial activity and quality. Continuous application of manure and fertilizer in tropical soils of India has shown that the soil organic carbon (SOC) and MBC increased with balanced fertilization whereas SOC, MBC, urease and acid phosphatase activities increased with organic amendments. Biological properties such as earthworm population, terrestrial arthropods, soil fauna and flora, lichen, microbial community (biomass or functional groups), metabolic products like ergosteroland glomalin, microbial respiration and enzyme activities have been used as soil quality indicators because of their intrinsic relationship with soil organic matter content which is central to soil health . There are several biological soil parameters that can be used as soil quality indicators, alone or in combination with other chemical or physical indicators. Proper sampling strategies and multivariate analysis of the results are key points to consider when using biological soil indicators. This chapter briefly discusses about the methods of soil quality assessment and importance and characteristics of biological indicators sensitive to land use changes and management practices.

There is significant variation in banana production systems across the world, particularly at the level of soil management. However, research on plant nutrition and soil management in relation to bananas has been limited for a number of reasons: bananas are unusual in their physiology and management, and the characteristics of the crop make it difficult to carry out standard fertilizer response experiments. Given the considerable investment in soil management, the scarcity of fertilization studies in bananas is surprising. This chapter provides an overview of general aspects of crop nutrition in the broader context of soil management. Focusing mostly on intensively managed systems where fertilizer use is the highest, the chapter discusses a number of strategies for soil nutrition as well as advantages and disadvantages of each approach.

Large-scale, monoculture production systems dependent on synthetic fertilizers and pesticides, increase yields, but are costly and have deleterious impacts on human health and the environment. This research investigates variations in banana production practices in Costa Rica, to identify alternative systems that combine high productivity and profitability, with reduced reliance on agrochemicals. Farm workers were observed during daily production activities; 39 banana producers and 8 extension workers/researchers were interviewed; and a review of field experiments conducted by the National Banana Corporation between 1997 and 2002 was made. Correspondence analysis showed that there is no structured variation in large-scale banana producers' practices, but two other banana production systems were identified: a small-scale organic system and a small-scale conventional coffee-banana intercropped system. Field-scale research may reveal ways that these practices can be scaled up to achieve a productive and profitable system producing high-quality export bananas with fewer or no pesticides.

Intensive agricultural practices lead to a deterioration in soil quality, causing a decline in farm productivity and quality, and disturbing the ecosystem balance in command areas. To achieve sustainable production and implement effective soil management strategies, understanding the state and spatial variability of soil quality is essential. The study aims to enhance the understanding of soil quality variability and provide actionable insights for sustainable soil management. In this regard, principal component analysis (PCA) and digital soil mapping were used to assess and map the spatial variability of the soil quality index (SQI) in the Cauvery command area, Mandya district, Karnataka, India. A total of 145 georeferenced soil samples were drawn at 0–15 cm depth and analyzed for physico-chemical properties. PCA was used to reduce the dataset into a minimum dataset as eight important soil indicators and to determine relative weightage factors, which were used for assessing SQI with linear and non-linear scoring methods. For spatial assessment of SQI, the random forest algorithm with environmental covariates was used to map eight soil indicators selected in the minimum dataset. The soil property maps were subjected to linear and non-linear scoring, followed by multiplying with corresponding weightage factors and summation to produce SQI maps. Results reveal that values of SQI calculated using linear scoring, range from 0.10 to 0.64, with a mean of 0.39, while non-linear scoring exhibits a wider range of 0.12 to 0.78 and a mean of 0.48. With a slight higher sensitivity index of 6.5, non-linear scoring proved to be the better scoring method compared to linear scoring. Spatial assessment shows that the R2 and LCC between the calculated and predicted SQI were higher for non-linear scoring (0.66 and 0.66) compared to linear scoring (0.60 and 0.65). The SQI maps reveal high spatial variability with more than 40 percent of soils classified as moderate-to-low index. The soils with low SQI were distributed in eastern parts, whereas western parts exhibited high-to-very-high soil quality. To achieve production goals and improve soil quality in the eastern region, sustainable soil and crop management strategies must be developed, and their effects on soil quality should be assessed.

The pathogen Fusarium oxysporum formae specialis cubense (FOC) has caused devastating economic losses in banana production systems. An improved understanding of how agronomic practices can affect the soil microbiome and related agro-ecosystem services, such as disease suppression, may assist in reducing impacts of FOC. This is the first study to investigate whether suppression of FOC, due to use of ground cover management in cultivation of Ducasse banana, is associated with changes in the soil microbiome. A field experiment was undertaken at a site where commercial production of Ducasse bananas had ceased due to Fusarium wilt (indicating high soil inoculum levels). Suppression of Fusarium wilt tended to increase with time in Ducasse bananas cultivated with ground covers compared to bare soil (the vegetated and bare treatments respectively). Terminal restriction fragment length polymorphism (TRFLP) and amplicon sequencing were used to profile microbial communities in bulk soils during the course of the field experiment. TRFLP analysis identified statistically significant changes in the structure of soil microbial communities over time in the vegetated treatment and identified potential bio-markers related to disease suppression. Fungal amplicon sequencing confirmed the findings of TRFLP, and demonstrated reduced dominance of FO in the vegetated treatment was associated with disease suppression. Limitations of using the ITS region for FO/FOC analysis were also determined. The results of this study provide an improved understanding of the mechanisms involved in suppression of FOC by use of ground covers in cultivation of Ducasse bananas, which may be useful for other agricultural production systems.

Evaluations of gross mineralization (MNorg) and nitrification (ONH4) can be used to evaluate the supply capacity of inorganic N, which is crucial in determining appropriate N fertilizer application. However, the relevant research for banana plantations to date is limited. In this study, natural forest and banana plantations with different cultivation ages (3, 7, 10, and 22 y) were chosen in a subtropical region, and the 15N dilution technique was used to determine the gross MNorg and ONH4 rates. The objective was to evaluate the effect of the conversion of natural forests to banana plantations on inorganic N supply capacity (MNorg + ONH4) and other relevant factors. Compared to other natural forests in tropical and subtropical regions reported on by previous studies, the natural forest in this study was characterized by a relatively low MNorg rate and a high ONH4 rate in the soil, resulting in the presence of inorganic N dominated by nitrate. Compared to the natural forest, 3 y banana cultivation increased the MNorg and ONH4 rates and inorganic N availability in the soil, but these rates were significantly reduced with prolonged banana cultivation. Furthermore, the mean residence times of ammonium and nitrate were shorter in the 3 y than in the 7, 10, and 22 y banana plantations, indicating a reduced turnover of ammonium and nitrate in soil subjected to long-term banana cultivation. In addition, the conversion of natural forest to banana plantation reduced the soil organic carbon (SOC), total N and calcium concentrations, as well as water holding capacity (WHC), cation exchangeable capacity (CEC), and pH, more obviously in soils subjected to long-term banana cultivation. The MNorg and ONH4 rates were significantly and positively related to the SOC and TN concentrations, as well as the WHC and CEC, suggesting that the decline in soil quality after long-term banana cultivation could significantly inhibit MNorg and ONH4 rates, thus reducing inorganic N supply and turnover. Increasing the amount of soil organic matter may be an effective measure for stimulating N cycling for long-term banana cultivation.

The rhizosphere is a microenvironment contrastingly different from non-rhizosphere soil. The high microbial activity in the rhizosphere leads to better cycling and availability of nutrients and improves chemical soil quality indicators. The biological soil quality indicators are improved in rhizosphere due to enhanced microbial activities either in terms of microbial biomass carbon, dehydrogenase activity, activities of various hydrolytic enzymes e.g., phosphatases, sulfatases, proteases, amidases and glucosidase responsible for breakdown of organically bound nutrients in soil. Over the last two decades lot of interests developed on soil quality research due to degradation in soil quality by anthropogenic activity. Besides being a rich source of carbon and energy for the heterotrophic organisms, plant roots exudates secrete a variety of carbonaceous materials that can act as a binding agent to increase stability of soil aggregates. The adoption of proper soil, crop, nutrient and organic manure management strategies has the direct impact on the soil quality. However, it may also be affected indirectly by the plant microbe interactions. This article focuses on induced changes in the rhizosphere ecology by plant microbe interactions and also to integrate these changes to soil quality indicator of unified soil in the sustainable agriculture soil management practices.

Energy and carbon footprints of ethanol production using banana and cooking banana discard: A case study from Costa Rica and Ecuador

In Cuba there is a strong differentiation in types of farming systems that operate at very different levels of management intensity. The aim of this research was to characterize differences in soil quality caused by different agricultural management systems and the effects of seasonality on soil chemical and biological indicators within representative farming systems in Santa Clara municipality, Villa Clara Province, Cuba. Two state farms, two cooperative farms, and three private farms, all located on brown calcareous soils, which differed in soil management and technological complexity were selected. Soil samples from two fields of each farm were collected to a depth of 20 cm. Laboratory analysis were performed to determine physical (aggregate stability, plasticity, and permeability), chemical (pH and organic matter), and biological (dehydrogenase and β-glucosidase activities) indicators of soil quality. We found significant differences in soil quality among the three farming systems, which were most pronounced between private and state farms, with respect to physical soil properties (aggregate stability and plasticity) and the activity of enzymes. Seasonality also exerted an important influence on the activities of dehydrogenase and β-glucosidase, which were greater in the rainy season. As a conclusion, we can say that the differences in soil management between the farming systems were reflected in consistent differences in soil quality indicators, notably between the state and private farms.

Soil quality (SQ) refers to its capacity to perform its functions. Thus, the SQ index (SQI) is a potentially useful tool for monitoring soil changes induced by mangrove restoration initiatives. Although the soil management assessment framework (SMAF) is a well-developed tool for SQ assessments in diverse ecosystems, it has never been tested on mangrove soils. In this study, we tested the SMAF to evaluate the shifts in the SQ of mangroves in a reforestation initiative using three- and seven-year plantations, which were compared with degraded and mature mangroves. A minimum dataset, composed of the pH and available P as chemical indicators, bulk density as a physical indicator, and soil organic carbon as a biological indicator, was used to calculate the SQI. The SMAF scores facilitated the monitoring of improvement in the mangrove SQ with vegetation development, mainly driven by physical and biological indicators. The SMAF may be a useful tool for monitoring SQ in mangroves under protection and recovery initiatives. Nevertheless, we suggest the inclusion of additional biological and chemical indicators in the minimum dataset for future studies to better represent specific processes and functions (e.g., microbial redox reactions and contaminant immobilization) that can alter the SQ of mangroves.