Tomato farmers in Nigeria, and indeed globally, constantly seek ways to improve crop yield, quality, and crucially, shelf life, as tomatoes are highly perishable. A recent screenhouse study published in The Scientific World Journal by Aruna Olasekan Adekiya, Timothy Oyebamiji Ogunbode, Vincent Ishola Esan, Olajire Adedokun, Iyabo Victoria Olatubi, and Modupeola Hellen Ayegboyin, investigates the impact of various calcium sources on soil properties, tomato growth, yield, and post-harvest quality. This research offers valuable insights for sustainable agricultural practices, especially in regions with light-textured soils and low cation exchange capacity (CEC), common in Nigeria.

The study tested five different calcium (Ca) sources: no fertilizer (control), calcium sulfate, calcium nitrate, poultry manure (PM), and cow bone biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More, all applied at a rate of 160 kg Ca ha−1. The initial soil analysis revealed a sandy loam texture with low organic matter, total nitrogen (N), available phosphorus (P), calcium, and magnesium (Mg), indicating a need for amendments to support optimal crop production.

The results demonstrated that all tested Ca sources positively impacted soil chemical properties, plant growth (height and stem diameter), yield (fruit number and weight), and the mineral content of tomatoes. Specifically, calcium sulfate significantly increased the soil’s Ca content. Compared to calcium nitrate, poultry manure, biochar, and the control, calcium sulfate boosted soil Ca by 1.25%, 9.82%, 20.11%, and an impressive 704%, respectively. This highlights calcium sulfate’s effectiveness in directly increasing calcium availability in the soil.

When it came to plant growth and overall yield, poultry manure emerged as the most effective amendment. Poultry manure increased plant height by 10.1% over calcium nitrate, 11.2% over calcium sulfate, 20.3% over biochar, and 45.2% compared to the control. More remarkably, tomato fruit yield increased by 22.5% relative to calcium nitrate, 20.16% compared to calcium sulfate, 83.4% over biochar, and a staggering 382.5% when compared to the control. This superior performance of poultry manure is attributed to its balanced nutrient supply, including macronutrients like N, P, and potassium (K), along with various micronutrientsThese are essential nutrients that plants need in small amounts, kind of like vitamins for humans. They include things like iron, zinc, and copper. Biochar can help hold onto these micronutrients in the soil, making them more available to plants.   More, which are released slowly as organic matter decomposes. This steady nutrient release and improved soil structure from organic matter enhance overall plant health and productivity.

However, the study also revealed a critical distinction in post-harvest quality. While poultry manure was highly effective for yield, calcium sulfate proved superior in extending the shelf life of harvested tomatoes and reducing weight loss. Calcium sulfate treatment reduced weight loss by 24.81% compared to calcium nitrate, 55.59% compared to poultry manure, 61.19% compared to biochar, and 104.99% compared to the control. Correspondingly, calcium sulfate increased shelf life by 14.78% over calcium nitrate, 29.79% over poultry manure, 36.42% over biochar, and 69.44% compared to the control. This effectiveness is largely due to calcium’s role in strengthening plant cell walls and maintaining membrane integrity, which helps to reduce water loss and slow down the ripening process by modulating ethylene production.

The findings suggest a promising integrated approach for farmers. Poultry manure can be applied at planting to leverage its benefits for soil fertility, plant growth, and fruit yield. Subsequently, calcium sulfate could be applied later in the growing cycle or during fruit development to maximize calcium availability, thereby enhancing shelf life and reducing post-harvest weight loss. This strategic combination could lead to not only higher yields and better-quality tomatoes but also longer shelf life, which is essential for reaching distant markets and minimizing economic losses from spoilage.

Source: Adekiya, A. O., Ogunbode, T. O., Esan, V. I., Adedokun, O., Olatubi, I. V., & Ayegboyin, M. H. (2025). Impact of Calcium Sources on Soil Chemical Properties, Tomato Growth, Yield, and Quality. The Scientific World Journal, 2025, Article ID 6653874.