Scaling up the use of organic fertilizers: two scenarios for Peru’s agri-food system

As we explored in our previous blog, all residues generated on the farm have value for preparing “food” for the soil, so their management should be grounded in the principles and practices of the circular economy and agroecology. Together, the application of a variety of organic-fertilizer techniques improves soil properties and contributes to the comprehensive nutrition of crops.

Through frequent application over time, agricultural communities can observe broad edaphic (soil- and plant-related), environmental, social, and economic benefits of organic fertilizers, as shown in the following table.

Table 1: Benefits of organic fertilizers

Level	Benefits of solid and liquid organic fertilizers
Edaphic (soil-related)	Improves soil texture and structure by enabling better aggregation of particles. Provides greater stability of soil aggregates. Improves soil porosity, facilitating good aeration, greater water infiltration, and better root growth. In sandy soils, significantly improves water retention, reducing irrigation frequency. Helps regulate soil pH due to its buffering capacity. Increases soil cation exchange capacity (CEC), contributing to better retention and efficiency in nutrient absorption. Significantly promotes soil biological activity. Increases the population of soil macro- and microfauna.
Environmental	Using solid and liquid organic residues as fertilizer reduces greenhouse gas emissions, especially methane. Proper management of organic residues reduces bad odors and the proliferation of vectors, improving sanitary conditions. Using livestock organic residues reduces nitrate leaching to groundwater. Proper use reduces soil contamination from seepage of unstable residues and reduces the release of tonnes of CO₂ to the atmosphere. Poor management will contribute to climate change through the release of tonnes of CO₂ per year. Poor management of organic residues can contribute to the disappearance of species. Poor decomposition of solid and liquid organic residues can contaminate the air with gases. Poorly managed organic residues increase the biochemical oxygen demand (BOD) of waters, affecting aquatic resources.
Social	Prevents harm to health, since poorly managed organic residues generate contaminants that enter people’s bodies through the trophic chain. By maintaining soil productivity, helps prevent displacement of populations due to degradation of living conditions in their place of origin. Sustained utilization can generate significant employment. Proper management helps strengthen producer organizations that generate the residues. Adding value to organic residues mobilizes different social sectors, including researchers and producers.
Economic	Adding value to organic residues improves the income of the families or companies involved. Utilizing solid and liquid organic residues fosters enterprises within the circular economy concept. Significantly improves soil productivity at lower cost. Does not create economic dependency, because production units can add value to their own residues.

At small and large scale: two pathways to increase soil fertility

A comprehensive soil-fertility management program should currently be developed under two strategically defined scenarios in order to manage plant nutrition adequately, with a view to guaranteeing sustained production and productivity in agricultural areas.

Family farming and food security

The first scenario relates to family farming, which is characterized by partial integration into the domestic market and by subsistence production, and which represents the largest number of production units in Peru. Under these conditions there are production systems with different technological levels, with potential and constraints—especially regarding soil fertility management.

Given the conditions under which agricultural activity is practiced (rugged topography, risks of drought and frost, degraded soils, and lack of vegetative cover), it is necessary to define proposals that enable converting these traditional production systems toward one that prioritizes ecological principles and improves their productive capacity.

Such a conversion should be oriented toward a sustainable agriculture model that, first and foremost, resolves issues related to food security. This requires creating a set of technical options based on the efficient use of resources available within the farming unit—through cycling and recycling biomass produced within the system—and incorporating simple, low-cost techniques that facilitate this process.

Commercial Agriculture: Technological Conversion and Productivity

The second scenario relates to commercial agriculture, closely tied to markets, characterized by high use of external inputs (fertilizers and pesticides). These systems are managed with short-term, high-profit approaches and do not account for environmental and social costs. They are fully open systems, and to return nutrients extracted by crops back to the soil, they rely on the massive use of synthetic fertilizers.

Under these conditions it is also important to propose mechanisms for technological conversion based on programs to reduce agrochemical use. Going forward, we should not sustain productivity by increasing fertilization doses; rather, we should focus on managing the soil ecologically through the interaction among the system’s components. From the Alternative Agriculture Action Network (RAAA) we consider that Peru has technologies that can be applied within the system to help, in the medium term, reduce these inputs.

To generate qualitative changes in both cases, differentiated transition processes are required depending on the system’s potentials and constraints. In traditional systems it will be necessary to implement farm designs and cropping plans based on conserving soil fertility; the interaction among agricultural, livestock, and forestry activities will be key to using space efficiently and achieving the cycling and recycling of organic resources on the farm.

In commercial, high-input agriculture, the first stage will require implementing input-substitution techniques (to the extent possible, greater use of organic inputs and reduced use of synthetic fertilizers). On the basis of this process, production should be organized toward diversification. This measure will enable complementary income streams within the system, which will be highly beneficial for the farmer.

To achieve conversion, there are currently technologies and experiences related to soil fertility management—many of which are practices that traditional agriculture has maintained over time. Among the techniques that can help initiate this process without generating additional costs, crop rotation and intercropping stand out. Simply implementing this practice generates a series of benefits for soil conservation and food security. It is also a starting point for reducing reliance on external inputs.

These techniques are complemented by the use of organic matter in its various forms (compost, vermiculture, organic foliar fertilizers, humic acids, and highly concentrated liquid fertilizers), as well as biofertilizers and minerals, which are increasingly being innovated and validated. While work is still needed to improve their efficiency and quality in enhancing soil fertility, it is clear that we already have an extensive compendium of techniques with which to begin the change.

However, it should not be overlooked that the choice of the best option for managing soil as a resource depends strongly on the underlying approach: if we adopt a productivist, “mercantilist” vision, neither the productive system nor soil fertility will be sustainable. If, on the contrary, we start from an integral approach, we will have greater options for addressing inherent risks within production systems.