Sweet Potato Cultivation: Advanced Techniques for Sustainable Production and Enhanced Nutrition

Edaphoclimatic Characteristics and Vegetative Propagation of Sweet Potato

The sweet potato (Ipomoea batatas), a tuber of great nutritional value and adaptability, represents a strategic option for gardens of various scales, from home use to larger operations. Its cultivation offers not only a versatile food source but also the opportunity to implement sustainable agricultural practices. This article explores essential techniques and recent innovations that optimize sweet potato production, addressing its relevance in current contexts such as food security and climate resilience.

Edaphoclimatic Characteristics and Vegetative Propagation

Site selection and substrate preparation are determinant for the success of sweet potato cultivation. The plant thrives in well-drained soils, with loamy to sandy textures, and an optimal pH between 5.5 and 6.5. The incorporation of organic matter, such as compost or worm castings, significantly improves soil structure, moisture retention, and nutrient availability, crucial aspects in regions with impoverished soils or in urban agriculture systems with artificial substrates. Recent studies by INTA in Argentina, for example, highlight the importance of balanced fertilization with an emphasis on potassium for optimal tuber development.

Sweet potato propagation is mostly done by stem cuttings, known as ‘slips’. These are obtained from mature sweet potatoes germinated in humid environments or from established mother plants. The process involves cutting stem segments of approximately 20-30 cm with at least 3-4 nodes, removing the lower leaves. The practice of rooting these cuttings in water or moist substrate before direct planting in the soil optimizes survival rates and initial development. This simple and effective technique allows growers to replicate desirable varieties and adapt the cultivation cycle to local conditions, an advantage in small-scale farming.

Water and Nutrient Management for Optimizing the Productive Cycle

Water management is a critical factor in sweet potato cultivation. Although the plant exhibits some drought tolerance once established, a consistent and adequate water supply is fundamental during the rooting and tuber development phases. The implementation of drip or soaker irrigation systems represents an efficient strategy, minimizing evaporation loss and ensuring water reaches the root zone directly. This technology not only optimizes water resource use, essential in a context of climate change, but also prevents foliar fungal diseases by avoiding excessive moisture on the leaves.

Regarding nutrition, the sweet potato is a demanding plant, especially for potassium and phosphorus for the formation of its tuberous roots. A prior soil analysis allows for the adjustment of necessary amendments. Practices like mulching with organic materials such as straw or pruning residues are highly beneficial. Mulching suppresses weeds, conserves soil moisture, and gradually adds nutrients as it decomposes, contributing to a regenerative agriculture approach. Constant monitoring for pests like the sweet potato weevil (Cylas formicarius) and foliar diseases using pheromone traps and the introduction of biological control agents are current strategies that reduce reliance on agrochemicals, aligning with organic and sustainable production trends.

Determining Harvest Time and Advances in Biofortified Varieties

Sweet potato harvest generally occurs between 90 and 150 days after planting, depending on the variety and climatic conditions. A key indicator is the yellowing and drying of leaves and stems. Extraction should be done carefully to avoid damaging the tubers, which can compromise their storage life. Appropriate tools and delicate handling are essential. After harvest, a ‘curing’ process for the tubers (keeping them at high humidity and temperature for a few days) improves their storage capacity and sweetness, strengthening the skin and healing small wounds.

The potential of the sweet potato expands with research and the development of new varieties. Institutions like the International Potato Center (CIP) are working on biofortification, developing varieties with higher content of vitamin A (orange-fleshed sweet potatoes), iron, and zinc, crucial for combating malnutrition in various regions. These advancements not only improve the nutritional profile but also aim for varieties more resistant to pests, diseases, and adverse climatic conditions, such as drought or salinity, offering resilient solutions for farmers. The integration of sweet potato into permaculture and urban agriculture systems, using techniques like container gardening or raised beds, demonstrates its versatility and adaptability to diverse environments, contributing to local food security.

Sweet potato cultivation transcends mere food production; it represents an agricultural practice with a profound impact on sustainability and nutrition. The application of optimized techniques, from soil preparation to harvest, combined with the adoption of innovations in varieties and resource management, positions this tuber as a cornerstone in the agriculture of the future. Its adaptability and nutritional richness make it a valuable component for any garden, promoting more robust and sustainable food systems.