VFRC Publications - Page 29

Pinning Down the Role of Micronutrients Promising search pathways for fertilizer solutions have been identified based on the review studies that are being pursued in several projects. These projects are supported by the VFRC through partial financial and intellectual input, serving the needs of both VFRC and the partner institutions and further consolidating the networks and collaborations. Application of micronutrients through leaves as foliar fertilizers rather than soil-applied is anticipated to significantly enhance uptake efficiency. This option, comparing soil and foliar micronutrient application, is being experimented under field conditions in Tanzania in concert with external collaborators. The prime emphasis is placed on how and in what packaging to deliver nutrients to crop plants to augment acquisition, translocation and utilization efficiency. These features are studied through various chemical forms in which P and Fe are packaged, i.e., complexed with various organic and inorganic substances, including chelates, polymers, nutrient solubilizing bacteria and organic acids. The uptake mechanisms through the leaves are studied through conventional observations and radio-isotopes. The modes of delivery being investigated include seed coating and soil and foliar application that are tested on cereal (rice), legume (soybean) and vegetable (lettuce) crops. These experiments are conducted in India and the Netherlands under advanced growth chamber and greenhouse conditions and in the field. These tests are also used to set standards and protocols for evaluation and scientific scrutiny of new products. The functionality of market-available specialty fertilizers containing micronutrients and biostimulants, aimed at high value markets in developed economies, is being tested under the greenhouse conditions of IFDC in the USA for use in food crops, as compared to conventional products. On-station testing and on-farm demonstration of different application methods of micronutrient-containing fertilizers to enhance yield and quality will be undertaken for rice in Uganda. The availability of nutrients in soil for plant uptake is not linearly related to measured soil nutrient contents, which hampers straightforward assessment of adequate fertilizer application rates. Research to more accurately relate soil nutrient content to fertilization rates under field conditions for Zn and Cu and, if possible, Mo and B, will be conducted whereby systems modelling and experiments in greenhouses will provide the analytical backbone. Results from hundreds of on-farm experiments conducted in Eastern African countries with micronutrient-containing fertilizers by IFDC have motivated VFRC to support their geo-spatial analysis for Burundi and Rwanda. This information will guide farmers on which balanced fertilizers to use and where they are to be applied. It will also guide agro-dealers on where to sell which fertilizer and help policymakers adapt their fertilizer policies for specific regions based on documented need and desired production volume increase. The impact of micronutrients as conventional fertilizers and as nanomicro-scale particles on yield and uptake efficiency of NPK, on disease suppression and on crop nutritional quality will be experimented in maize, tomato, eggplant and cucumber under controlled conditions. High-resolution microscopy and spectroscopy will be used to detect the form of nutrients in plant tissues. 25