How Soil Moisture Impacts Your Garden


Gardening is a tough job that seems equally easy to someone who hasn’t done it before. From compost and soil aeration to the quality of the topsoil and other such factors need to be accounted for. If you need topsoil for your garden, you can search for “topsoil near me” and buy some from the local store. For now, let’s check out how soil moisture affects you.

The Impact

  1. Plant growth – Plants accumulate plenty of dry matter from the soil by tapping into its water supply. The amount of dry matter that can be accumulated changes all the time and depends on various factors including the thickness of the stem, plant height, yield, and leaf area. When the soil doesn’t have enough water, plants can’t gather those essential resources and suffer from stunted growth. Photosynthetic activity on leaves also decreases and you also get a lower yield from your veggies garden.
  1. Yield – Crop yield depends on how much solar energy can be transformed by the plant into chemical energy and accumulated into the crops. When the soil moisture level is low, roots don’t have enough water to absorb and that also reduces transpiration from the leaves. This creates a vicious cycle that leads to reduced photosynthesis levels and dry matter accumulation and affects crop yield negatively.
  1. Leaf area – Plants are able to stay cool with the help of transpiration and create food by photosynthesis. Most of that happens on the leaves. However, leaves are very sensitive to moisture levels. Without adequate moisture levels in the soil, leaves don’t have enough water to maintain a high turgor pressure in the tissues and hence can’t stay upright.

That’s why you’ll find most of the leaves wilting downward if there is not enough moisture in the soil. When this happens, the leaf area exposed to the sun is reduced significantly and mesophyll cell expansion that allows free movement of carbon dioxide for photosynthesis is also limited. This leads to stunted growth, low yield, adverse health impacts, and more.

  1. Root and shoot development – There are several factors that affect root health and development. However, the primary factors are soil aeration and soil moisture levels. When soil moisture levels are high, most roots get an adequate distribution of water. The high soil moisture level also decreases resistance to root development and growth.

However, when soil moisture levels are low, the root prioritizes itself and meets its own needs before sending the rest above the ground. That’s why if soil moisture levels are low, you’ll have more roots than shoots on your plant. On the other hand, if the soil has excessive amounts of moisture, the shoot-to-root ratio increases drastically. It also increases overall root weight and can inhibit the growth of the parts above the ground.

However, studies show that water deficit is good for the plant in its early stages. Research shows that if soil moisture levels are low during the early stages of growth, the plant becomes more drought resistant. However, an extended period of water deficit after the initial growth stage is bad for both root and shoot development, weakens the plant, and reduces crop yield.

  1. Photosynthesis – As mentioned above, low soil moisture levels affect photosynthesis. It is the process that allows plants to create food and energy from sunlight and is very closely linked to the water status of the plant. Research shows that when plant tissues are saturated with water photosynthesis rate is at its peak. However, if the water content is too much, stomata are closed passively and that stops photosynthesis temporarily.

When the plant doesn’t have enough water, the photosynthesis rate takes a hit. It gets reduced drastically when the leaves are wilted due to insufficient turgor pressure. With low moisture levels, water potential on leaves decreases, and stomata resistance increases which hinders CO2 diffusion and photosynthesis. If the leaves on your plant are wilting and turning yellow, it may be due to low or excess soil moisture.

  1. Organic matter transportation – Low soil moisture leads to reduced water potential on leaves and that decreases the assimilation materials transported from the source leaf to the phloem. This happens since mesophyll cells can’t expand properly and that leads to lower sucrose levels that can be transported. Reduced organic matter transportation also happens due to the reduced speed of mass flow in the sieve tube.

Water is directly responsible for both transportation and transformation of certain materials in the plant and it is also actively used by the plant in many biochemical reactions. The plant is prepared for low moisture levels when it is swelling and filling up fruits and crops. In other cases, drought conditions are abnormal for the plant and can affect its growth and regeneration capabilities.

Too much water in the soil isn’t great for the plant either. When there’s too much water in the soil, it reduces air pockets in the soil and that affects the respiration of roots and other important metabolic processes.

  1. Seed germination – All experienced gardeners and anyone who has ever tried to grow something from a seed know that water is the most important factor in seed germination. Seeds require a massive amount of water to germinate and grow into a sapling. Water is required to soften the seed coat and swell it up. This allows oxygen to penetrate the coat and increases respiration for the embryo. A softened seed coat also allows the embryo to break apart the coat with ease. You can never germinate a seed on dry soil.


Soil moisture has a literal and metaphorical deep impact on your plants. From its metabolism to root health and ability to create food, everything is affected by soil moisture levels. That’s why you need to set up a good irrigation system and take other measures to make sure that soil moisture level is maintained at adequate levels. On the other hand, you can search for “topsoil near me” and buy some from a local store to create a new garden bed.