How to Calculate Plant Water Requirement

Plants need water to survive and thrive. Water is essential for photosynthesis, the process by which plants create their own food. But how much water do plants need? It depends on a variety of factors. Calculating plant water requirement can seem daunting, but it's actually quite simple.

Step 1: Determine the Water Requirement of the Plant Species

The first step in calculating plant water requirement is to determine the water requirement of the plant species. Different plant species have different water requirements. Some plants prefer a lot of water, while others can survive with very little water. You can usually find information on the water requirements for specific plant species from a gardening or plant care book, or you can ask a gardening expert or horticulturist.

Step 2: Determine the Climate in Which the Plant Is Growing

The second step in calculating plant water requirement is to determine the climate in which the plant is growing. Climate can have a big impact on how much water a plant needs. For example, plants that grow in hot, dry climates will need more water than plants that grow in cooler, wetter climates. It's important to take into account the average temperature, humidity, rainfall, and wind speed when calculating plant water requirement for a specific location.

Step 3: Determine the Soil Type and Quality

The third step in calculating plant water requirement is to determine the soil type and quality. Soil can have a big impact on how much water a plant needs. For example, sandy soils drain quickly and don't hold much water, so plants growing in sandy soil will need more frequent watering than plants growing in loamy soil. It's important to take into account the soil texture, structure, pH, and nutrient content when calculating plant water requirement for a specific location.

Step 4: Determine the Stage of Growth of the Plant

The fourth step in calculating plant water requirement is to determine the stage of growth of the plant. Different stages of growth require different amounts of water. For example, seedlings and young plants require more frequent watering than mature plants. It's important to take into account the plant's growth stage when calculating plant water requirement.

Step 5: Calculate the Plant Water Requirement

Once you have determined the water requirement of the plant species, the climate, the soil type and quality, and the stage of growth of the plant, you can calculate the plant water requirement. There are several methods for calculating plant water requirement, but one common method is the "checkbook" method.

The "checkbook" method involves keeping track of how much water the plant is receiving and how much water is being lost through evapotranspiration (the combined loss of water through plant transpiration and evaporation from the soil surface). The goal is to keep the "bank balance" positive – in other words, to make sure that the plant is getting enough water to meet its needs without wasting water.

To use the checkbook method, you'll need to calculate the daily water requirement of the plant based on the factors you've determined in steps 1-4. Then, you'll need to measure the amount of water that the plant is receiving each day and the amount of water that is being lost through evapotranspiration. If the plant is receiving less water than it needs, you'll need to water it more. If the plant is receiving more water than it needs, you'll need to cut back on watering.

In Conclusion

Calculating plant water requirement is important for ensuring that your plants stay healthy and thrive. By taking into account the water requirement of the plant species, the climate, the soil type and quality, and the stage of growth of the plant, you can calculate the plant water requirement using the "checkbook" method or another method that works best for you. Remember to adjust your watering schedule as needed based on the results of your calculations. Happy gardening!