Growing Tomato crop nutrition advice

What soil type, pH and climate do field tomatoes prefer?

• Soil Type: Tomatoes thrive in well-drained, light-colored, loose, friable sandy loams with high levels of organic matter. These soils promote healthy root development and efficient nutrient uptake. Well drained soil helps reduce incidences of diseases such as bacterial wilt.
• Soil pH: Tomatoes perform better in soil with a pH between 5.5 and 6.8 with the optimal pH range for tomatoes is between 6.2 and 6.8. Soil pH significantly influences nutrient availability; pH levels above 7.5 can lead to deficiencies in boron (B), copper (Cu), iron (Fe), manganese (Mn), phosphorus (P), and zinc (Zn). Conversely, soil pH below 5.5 increases the likelihood of deficiencies in phosphorus (P), molybdenum (Mo), and calcium (Ca).
• Climate: Tomatoes perform best at temperatures between 64°F and 81°F. High temperatures above 93°F can negatively impact pollination and fruit set, particularly when coupled with inadequate water supply.
• Moisture Needs: Proper watering practices are crucial, particularly during transplanting, flowering, and early fruit development. Field-grown tomatoes require approximately 16 to 24 acre-inches of water for field production, with peak demand occurring from transplanting to fruit setting. Water requirements are highest during early fruit development and significantly lower during ripening. A minor water stress during ripening can enhance fruit firmness, sugar content, taste, and shelf-life, though it may reduce fruit size.
• Irrigation Practices: Efficient irrigation is crucial for successful tomato production. Drip irrigation has become the standard practice, as it offers excellent water use efficiency and can be effectively combined with plastic mulch to conserve moisture and control weeds. Growers can focus on critical watering stages: transplanting, flowering, and fruit development, ensuring that moisture levels are consistent to avoid issues such as flower and fruit drop, sunscalding, and dry rot. To improve water-use efficiency soil surfactants (like H2Flo) trials on tomatoes in Florida have shown to improve both water conservation, energy-use and yields.

Nutrient requirements

Estimated nutrient uptake (kg/t):

Source: IPNI

Dynamic of nutrient uptake over a crop season in tomato

Key Nutrients for Tomatoes

• Nitrogen (N): Crucial for vegetative growth, nitrogen promotes leaf and stem development. Recommended nitrogen application rates vary by soil type: Coastal Plains soils typically require 150 to 200 pounds per acre, while Piedmont, Mountain, and Limestone Valley soils may need only 100 to 150 pounds. Excessive nitrogen can lead to delayed maturity and poor fruit quality.
• Calcium (Ca): Essential for cell wall structure and preventing blossom-end rot (BER). Calcium has limited mobility in the soil, so thorough incorporation of lime to a depth of 6 to 8 inches is necessary to ensure its availability.
• Magnesium (Mg), Sulfur (S), Zinc (Zn), and Boron (B): Supplement as needed based on soil tests. Dolomitic limestone can address both magnesium and pH concerns. Polysulphate can also be incorporated to support sulfur, magnesium and calcium needs.
• Starter Solutions: Utilizing fertilizer materials dissolved in water at transplanting can promote rapid root development and early growth. All phosphorus and about 50% of nitrogen and potassium should be applied for effective fertilization before laying plastic mulch. Low-acidity solutions, like Agrolution High K CalMag 11-6-20 +6Ca +1.5Mg, can provide elevated ratio of potassium plus calcium and magnesium plus fully chelated micros, in a non-acidic water-soluble fertilizer that promotes healthy fruit set and improves fruit quality and stalk strength. Agrolution phLow High K Plus Ca acidifying fertigation and pH management solution provides an elevated potassium-to-nitrogen ratio, a base level of all micronutrients, plus an extra boost of calcium. Polysulphate can be applied at pre-plant to help prevent typical calcium and magnesium deficiencies

Role of nutrients

(*) Excess of N fertilization can delay the reproductive stage

Role of Nutrients in Tomato Crop Production

Tomatoes require a balanced supply of essential nutrients for optimal growth and fruit quality. Each nutrient plays a specific role in various physiological processes:

• Nitrogen (N): Crucial for robust vegetative growth, nitrogen is a key component of enzymes, vitamins, and chlorophyll. It significantly influences all growth stages, promoting early growth, supporting flower development, and maintaining fruit fill. However, excessive nitrogen can lead to rank vine growth, delaying fruit set and compromising shipping quality.
• Phosphorus (P): Vital for influencing both yield and quality, phosphorus is a component of nucleic acids (DNA and RNA) and plays a direct role in energy transfer within the plant. It enhances overall yield and fruit quality by increasing Total Soluble Solids (TSS), or Brix.
• Potassium (K): Essential for maintaining ionic balance and water status, potassium impacts yield and quality. It aids in nutrient uptake, sugar production and transport, and fruit development. Inadequate potassium may cause uneven ripening and quality issues, while higher levels can increase the acidity of tomato juice.
• Calcium (Ca): A key component of cell structure, calcium is vital for preventing blossom-end rot and ensuring proper fruit development. Low calcium levels can disrupt fertilizer uptake and adversely affect growth rates.
• Magnesium (Mg): Important for photosynthesis, magnesium supports chlorophyll synthesis and energy transfer. Deficiency can lead to stunted growth and impaired overall plant health. Magnesium also plays a role in improving flowering and crop production.
• Micronutrients: Essential for flowering and fruiting processes, micronutrients like boron and zinc are critical for overall plant health. Their deficiencies can result in reduced yields and poor fruit quality.

Nutrient deficiencies

Source: https://vikaspedia.in

Nutrient Interactions

Nutrient interaction considerations are crucial in tomato crop nutrition planning, as they are for many plants. For example, potassium (K) can negatively affect magnesium (Mg) absorption more than Mg affects K. This means it’s important to balance K and Mg fertilizers to ensure enough available Mg while avoiding K-induced Mg deficiency. This is especially important for tomatoes, which need a lot of potassium, and in soils rich in potassium (Xie et al., 2021). Furthermore, using too much ammonium (NH4) can harm plant growth and cause calcium deficiency (Bonomelli et al., 2021).

• University of Georgia Cooperative Extension. (n.d.). Commercial tomato production handbook. https://extension.uga.edu/publications/detail.html?number=B1312&title=commercial-tomato-production-handbook
• University of Tennessee Institute of Agriculture. (2022). Commercial tomato production. https://rutherford.tennessee.edu/wp-content/uploads/sites/200/2022/05/pb737-Commercial-Tomato-Production.pdf
• Bonomelli, C., de Freitas, S. T., Aguilera, C., Palma, C., Garay, R., Dides, M., … & O’Brien, J. A. (2021). Ammonium excess leads to Ca restrictions, morphological changes, and nutritional imbalances in tomato plants, which can be monitored by the N/Ca ratio. Agronomy, 11(7), 1437.