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