Association between nutrients uptake and pant growth

• Region A/deficient zone: crop production increases with soil nutrient concentration due to increase nutrient usage by the plant as soil nutrient concentration increase.
• Region B/Optimum zone: crop production almost remains constant as soil nutrient concentration because the plant achieves enough/adequate/optimal nutrient concentration. This zone is most suitable for feeding the pasture plants to livestock due to high pasture yield and quality.
• Region C/toxic zone: Biomass yield decreases because excessive nutrients lower biomass yield due to toxicity such as soil acidification, mineral antagonism and reverse osmosis in roots, reducing soil fertility and capability to support plant growth.

Other factors that may affect shape the graph above or affect biomass yield of plants are.

• Soil water: soil provides water to plant which is a reagent in many biochemical reactions. However optimal amount is required because too little water may not be absorbed by plant while too much water reduces the amount of air in the soil.
• Soil air: this provides oxygen for root and microorganisms’’ respiration and nitrogen for fixation by root nodules.
• Light: increase in light intensity increases biomass yield
• Prevailing carbon dioxide concentration in air: high concentration of carbon dioxide in air increases biomass yield.
• Soil microorganism: these play a role in soil aeration, recycling of nutrients, and provision of nutrients to plant when they die and decompose
• Temperature: promote plant growth by activating enzymes. At very low temperature the enzymes are inactive while at very high temperature the enzymes are denatured, and the plant dies.
• Soil pH affects activity of enzymes; optimum pH necessary depending on plant type
• Soil structure: this is the proportion of sand, silt, and clay in a particular soil. Soil’s structure determines water retention and aeration of the soil. Plants prefer different soil structure.
• Soil pollution: this may affect the micro and macro-organisms’ content and quality, pH and other soil contents and interaction.

Note that under normal conditions, nutrient uptake determines plant growth in predictable way during most of crop’s growth.

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Dr. Bbosa Science