Importance of Nitrogen and phosphorus to plants
Phosphorus and nitrogen is considered the essential nutrients required by the plants. They are required in larger quantities and thus known as the macronutrients. Each of the nutrients has its specific roles in plant development. Nitrogen mineral is the major component of most of the organs in plants. It constitutes approximately 40% to 50% of the dry matter of protoplasm, composes amino acids. It is also considered the major constituent of the building blocks of proteins. The nitrogen deficiencies result in slower or stunted growth and visible effects chlorosis (Nurzyńska-Wierdak et al., 2012). The plants that have been in an environment with little nitrogen soils have purple-coloured stems, the underside of the leaves and the petioles due to the accumulation of the anthocyanin pigments.
The nitrogen and phosphorus nutrients are very important and are both needed in the as the building blocks of the proteins, cellular constituents and nucleic acids. These include the enzymes and the chlorophyll matter. The Phosphorus nutrients are used by the plant in carrying out all the vital processes. The processes include the development of the deoxyribonucleic nucleic acid (DNA), nucleic acids, and Ribose nucleic acid (RNA). It is also involved in the structural building and development of the fatty phospholipids that are of importance in the development of the cell walls and the cell membranes and their functions (Constán-Aguilar et al., 2014).
Levels of the nutrients in the plants and their effects on Brassica Rapa Plant Biomass
The documented research on biomass response of Brassica Rapa sub species (Solanum retroflexum) to nitrogen, phosphorus and potassium revealed that increased nitrogen application rates increase total fresh and oven dry above ground (shoot) biomass until the rate of 150 kg N/ha. Higher than 200kg N/ha can cause a sharp decline biomass. Increased phosphorous application rates increased total fresh and oven dry aboveground biomass of S. retroflexum until the rate of 100 kg P/ha. At phosphorus application rates of higher than 100 kg P/ha, both fresh and oven-dry biomass reducing sharply far below the highest values, reached at 100 kg P/ha (Torres et al., 2013).
The importance of understanding the effects of Nitrogen and Phosphorous
The effect of each of the two nutrients on plants has been observed to be significant. The interaction effects are highly significant, and thus, the optimal combination of the two nutrients for improved shoot and root biomass is nitrogen at 98 kgN/ha, phosphorous at 61 kg P/ha. Both Nitrogen and phosphorous leads to improved shoot and root growth, but they both lead to a faster rate of shoot development that the roots. Thus, understanding their effects help the plant pathologists in enhancing the desired growth properties in crops and plants.
References
Constán-Aguilar, C., Sánchez-Rodríguez, E., Rubio-Wilhelmi, M. M., Camacho, M. A., Romero, L., Ruiz, J. M., & Blasco, B. (2014). Physiological and Nutritional Evaluation of the Application of Phosphite as a Phosphorus Source in Cucumber Plants. Communications in Soil Science and Plant Analysis, 45(2), 204-222.
Nurzyńska-Wierdak, R., Dzida, K., Rożek, E., & Jarosz, Z. (2012). The effect of nitrogen and potassium on N-NH4 and n-NO3 accumulation and nutrient contents in rocket (Eruca sativa Mill.) leaves. Acta Sci Pol-Hortoru,11, 211-221.
Torres Elguera, J. C., Yañez Barrientos, E., Wrobel, K., & Wrobel, K. (2013). Monitoring of Phosphorus Oxide Ion for Analytical Speciation of Phosphite and Phosphate in Transgenic Plants by High-Performance Liquid Chromatography–Inductively Coupled Plasma Mass Spectrometry. Journal of agricultural and food chemistry, 61(27), 6622-6628.
