EFFECT OF THE METHOD AND LEVEL OF ADDING NPK NANOPARTICLES AND MINERAL FERTILIZERS ON THE GROWTH AND YIELD OF YELLOW CORN AND THE CONTENT OF MINERAL NUTRIENT OF SOME PLANT PARTS

A field experiment was conducted during the autumn agricultural season of 2018 in Shomali district, 68 km southeast of Hilla city, within 32.18 degrees north latitude and 44.18 degrees east longitude, during autumn season 2018. To know the effect of NPK (20:20:20) nanoparticle and mineral fertilizer adding methods and fertilizer levels on the growth and productivity of corn Zea mays L. , The experiment was conducted according to the Complete Randomized Blocks Design with three replications. the averages were compared according to Duncan polynomial test at a probability level of 0.05%. The results showed the following: The spraying treatment with NPK nanoparticles (1.5g.L 7.5 kg.ha) mixing with soil was significantly excelled in vegetative growth and yield by giving the highest mean in plant height (191.2 cm), the total number of leaves (16.07 leaves.plant), The leaves area index (0.391), plant content of total chlorophyll (60.17 SPAD), number of grains per cop (632.7 grains.cob), weight of 500 grains (186.7 g), grain yield (11.38 tones. ha) and biological yield (23.07 Ton.ha. The spraying treatment with NPK nanoparticles 1.5 g.L + 7.5 kg.ha mixing with soil achieved significantly increased and recorded the highest averages in root content of nutrients (N, P, K) amounted to 0.412, 0.143 and 0.427 g. Leaves 5.712, 1.088 and 4.397 g.plant-, respectively, and the absorption rate of these elements amounted to 38.39, 7.73 and 30.19 mg.plantand the transfer rate of those elements above which amounted to 35.85, 6.85 and 27.56 g . plant. Day -1 respectively. Keyword : Zea mays L, NPK nanoparticles ,mineral fertilizers Introduction Corn is one of the important strategic crops in Iraq and the world, and It ranks third order after the wheat and rice crops in the cultivated area and productivity, Corn has many uses, which are directly or indirectly in human food, and used as an essential ingredient in animal feed and diets, in addition to nutritious, medicinal, and other industrial purposes, so it is known as the queen of grain crops (Bukhsh et al., 2010). The productivity of grain crops, including corn, is greatly influenced by the availability and abundance of the essential nutrients NPK necessary for plant growth and production. Nitrogen is the main component of protein and protoplasm that has a Biologically role in increasing plant biomass (Meharg and Marschner, 2012). the lack of supplying the plant with nitrogen leads to reduces plant size and disrupts many bio-functions (Muchow and Davis, 1988). Phosphorus is the second largest nutrient identified for crop production after nitrogen, and crop response to nitrogen is influenced by plant phosphorus availability (Goulding et al., 2008). It is directly involved in many physiological processes such as photosynthesis, cell division, grain formation, production of energy compounds, nucleic acids and protein, stimulating root growth and promoting crop growth (Havlin et al., 2005). Potassium plays an essential role in the effectiveness of enzymes, photosynthesis, osmotic regulation, protein synthesis, stomatal closing and opening mechanism, ion balance, energy transfer and stress resistance in the plant (Marschner, 2011). The adding of mineral fertilizer NPK is necessary to increase the growth and yield of corn, but the traditional method, in adding, do not without problems, The use of mineral fertilizers continuously and rapidly decomposition and loss of quantities of nutrients through volatilization or washing and filtration or converted into complex compounds, It cannot be used by the plant. It is also harmful to soil and the environment as it leads to increased soil acidity, nutrient imbalance and groundwater pollution (Stewar et al., 2005). Therefore, it is necessary to use the best modern methods and techniques to supply the plant with nutrients. These techniques are the technique of using nano fertilizers, including balanced NPK nano fertilizer and adding them either by spraying the total vegetative or mixing it with the soil or using them together. Nanotechnology can provide the solution to increasing the value of agricultural products and environmental problems by using fertilizers with nanoparticles with sizes (1-100 nanometers). Thus we can control the release of mineral elements added as fertilizers, The basis of the work of nano fertilizers is the rapid supply of nutrients and increase the duration of the fertilizer effect. Nanotechnology has a significant impact on improving the solubility of other soil elements, displacing and replacing insoluble elements, reducing nutrient mineralization, increasing bioavailability and Easily absorbed by the plant (Naderi and Danesh-Shahraki, 2013). Materials and Methods A field experiment was conducted during the autumn agricultural season of 2018 in Shomali district, 68 km southeast of Hilla city, within 32.18 degrees north latitude and 44.18 degrees east longitude, To know the effect of NPK (20:20:20) nanoparticle and mineral fertilizer adding methods and fertilizer levels on some growth indicators of growth and yield of corn and the content of some plant parts of nutrients N, P, K and measure the rates of absorption and transfer of those elements for the corn crop( cultivar Furat). Soils sample were randomly taken and analyzed for some physical and chemical traits as shown in Table (1). Table 1: Some physical and chemical traits of field soils Unit Value Traits 322.4 g.k sand 447.4 g.k Silt sandy silt loam 230.2 g.k Clay g.k 1.86 Organic matter mg.k 68.32 Nitrogen availability mg.k 10.28 phosphorus availability mg.k 204 Potassium availability ds.m 1.15 EC