Research & Development (R&D)
Green plants have the ability to manufacture their own food by using energy derived from the sun to combine chemical elements, taken up in the inorganic ion form, into a multitude of organic compounds. These elements are considered essential for plant growth. If any of these 16 elements are lacking, plants cannot complete their vegetative or reproductive cycles. Some of these nutrients combine to form compounds which compose cells and enzymes. Others must be present in order for certain plant chemical processes to occur.
PRIMARY FERTILIZER ELEMENTS
SECONDARY FERTILIZER ELEMENTS
Carbon, hydrogen and oxygen are supplied to the plants through air and water. These three elements comprise about 95% of the total dry matter of most plants. The remaining 5% of the dry matter is made up of 14 essential mineral elements along with many other elements that may be taken up in small amounts by the plants but are not know to perform any essential functions within the plant.
When plant growth is limited because of lack of an essential element it is usually due to a deficiency of one or more of these 14 elements. These elements are primarily taken up by plants from the soil solution.
The 14 mineral nutrients required for plant growth are classified as primary, secondary, or micro-nutrients according to the quantity required by plants and/or how widespread deficiencies of the nutrients are Primary nutrients are used in the largest quantities and are usually the first to become deficient in the soil. Primary nutrients and the secondary nutrients are sometimes known as macro nutrients.
Secondary nutrients are macro-nutrients but are less frequently deficient in soils.
Micro-nutrients, also known as trace or minor elements, are required in very small amounts and are less frequently deficient. Even though nutrients are used in different amounts, each of the essential nutrients is equally important for plant growth.
Nutrient uptake precedes dry matter accumulation because nutrients are required for plant growth and hence dry matter accumulation.
Root development of crops
Crops obtain nutrients and water from the soil through their roots. Roots of plants normally continue to grow as long as soil conditions such as moisture, air, nutrients, temperature, soluble salts and tilth are favorable. If unfavorable conditions exist, root growth will be limited. The most common inhibitors of root growth are dry soil, lack of soil air because of excess water and poor drainage, and soil compaction.
Roots will not grow in dry soil. If there is a layer of dry soil between moist topsoil and deeper moist subsoil, the root system of annual crops will expand only in the moist area above the dry soil. The deep, “carryover” moisture will not be used. Perennials, with root systems already established in the deep, moist subsoil will be able to use this moisture.
Plant roots absorb nutrients in their ionic form. The best placement of fertilizer, the movement of nutrients to the root, and the factors affecting root uptake depend on the mobility of these ions and the rooting characteristics of the crop. Plant roots absorb nutrients from the water film around soil colloids. Immobile nutrients which are relatively insoluble or are held tightly by the soil exchange complex will not move very far through the water to the root. Phosphate, for example, will move only a fraction of an inch. For immobile nutrients, such as P and K, fertilizer must be placed in the root zone where roots are growing.
Immobile nutrients move to the root surface mainly through a process called diffusion. Diffusion is the movement of ions from a zone of high concentration to zones of lower concentration. As plant roots absorb nutrients from soil water, ions diffuse toward the roots as a result of the lower ionic concentration near the root. Diffusion operates only across very short distances.
Mobile nutrients move to the root surface largely with the flow of water into the plant and is termed mass-flow. As plants extract water, water moves toward the root and carries mobile nutrients with it. Mass flow allows plants to absorb mobile nutrients that are not initially close to the roots.
Another factor affecting nutrient uptake by plants is root interception, or growing of roots into unexplored soil zones.
Soil Organic Matter
Soil organic matter and humus are terms which refer to the partially decomposed residue of plants, animals, and other organisms. Organic matter refers to all organic material including fresh crop residues. Humus is the more stable decomposed organic residue. Organic matter has long been recognized as having many beneficial effects on physical and chemical properties of the soil.
Some important effects of organic matter are as below:
• Improves Soil Structure. Organic matter acts as a bonding agent which holds soil particles together in aggregates. Without organic matter, aggregates are less stable and are easily broken apart. Good soil structure promotes water movement and root penetration while reducing soil crusting, clod formation, and erosion.
• Contributes to Cation Exchange Capacity (CEC), soil organic matter has great ability to attract and hold cations
• It Provides Plant Nutrients and one of the most important attributes of organic matter is its contribution to soil fertility. Approximately 90% to 98% of the total N and S and 30% to 50% of the P exist in the soil in organic forms.
Site Specific Nutrients Management
⦁ Site-specific nutrient management (SSNM) is the dynamic, field-specific management of nutrients in a particular cropping season for optimizing the supply and demand of nutrients.
⦁ This approach aims to increase profit through high yield and enhanced nutrient use efficiency, and also provides a locally-adapted nutrient best management practice.
⦁ Soil Health Management- (Principal of 4 R’s) Right Rate, Right Source, Right Time, Right Method
We are working for development of technology using sensors-based farming for direct detection and monitoring for N, P, K, and Electric Conductivity (EC) of soil and pH for water.