Pumice in Agriculture
Aeration and water retention capacity are the most important physical properties in plant growing media. Plant roots require air for respiration. Air is essential for metabolic processes in living organisms. Inadequate oxygen and aeration weaken the plant, slowing growth and making it more susceptible to cold damage and disease. Aeration is also required for the diffusion of carbon dioxide, generated from the respiration of root cells and microorganisms, from the roots to the soil surface. Water retained in the medium is essential for plant growth and other physiological processes. Therefore, a continuous and adequate supply of water is crucial.
Aeration and water retention are primarily a function of medium porosity. Porosity consists of large and small pores. Large pores are important for aeration and drainage, while small pores are important for water retention. Plant growth is significantly limited when the amount of air-filled pores falls below 10%. Aeration porosity should be at least 20-25%. This value can reach up to 45% in hot greenhouse conditions due to increased oxygen demand and carbon dioxide production by roots. Increased aeration reduces water retention. However, frequent irrigation is preferred over poor aeration for growing.
The physical properties of the medium are not constant, as they can vary depending on the conditions. Significant changes occur in physical properties such as bulk density and porosity, depending on particle size distribution. Compaction is another important factor affecting these properties. Compaction causes an increase in bulk density and a decrease in large pores. Therefore, in addition to selecting the appropriate particle size distribution in the medium, it is also important that the material is stable against changes that may occur due to compaction over time.
Pumice (pumice) is a widely used material as a plant growth medium. Its physical and chemical properties are stable. This allows for its repeated use. It is also lighter than soil, making it easy to process, transport, and use on-site. There are significant reserves of pumice (pumice) in Turkey and many other parts of the world. World production of pumice (pumice) in 2002 was 13 x 106 tons. Turkey's average annual production is 1.5-2 x 106 tons.
The aim of this study is to determine the properties of pumice (pumice) material from various regions of Turkey in terms of aeration and water retention capacity and to demonstrate its potential for use in agriculture. In conclusion:
Pumice (pumice) materials from all regions are sufficient in terms of aeration and water retention capacity and can be used as plant growth media. Using fine, single-dimensional material reduces aeration and increases water retention capacity, while using coarse material, conversely, increases aeration and decreases water retention capacity. However, using mixed materials can easily achieve much better values for aeration and water retention capacity. Therefore, using mixed materials rather than single-dimensional materials is more appropriate. In greenhouse conditions, where root aeration is crucial, environments with a high concentration of coarse material are preferred because they provide greater aeration.
Y. Kuşlu, Ü. Şahin, Ö. Anapalı & S. Şahin
Atatürk University, ERZURUM