Could nanospheres reduce the amount of conventional nitrogenous fertilizer by 65%?

08/02/2016

Aleana Ledezma Delgadillo, a PhD student at the Center for Research in Applied Science and Advanced Technology of the National Polytechnic Institute (CICATA-IPN), developed nanospheres made with a biopolymer that allows to reduce 65 percent the amount of nitrogen fertilizer that is conventionally used to nourish a plant, without affecting its growth and development.

The researcher is convinced that her innovation will benefit the agricultural sector and the environment. "In the agricultural area, it helps producers in the amount they use for fertilizer, decreasing the expense they make to buy it and, consequently, food costs are reduced, because in any vegetable these nanospheres can be used. And in the environmental area we reduce the damage that is being caused to the soil (by the use of fertilizers) ".

The scholar of the National Council of Science and Technology (Conacyt) is currently staying at the Technological Institute of Tepic (ITT) and is advised by Dr. Eduardo San Martín Martínez, of CICATA-IPN, Mónica R. Jaime Fonseca, also of CICATA -IPN, Rogelio Carrillo González, from the College of Postgraduates in Agricultural Sciences (Colpos-Texcoco), and Alejandra Chacón López, from ITT.

The ammonium nitrate fertilizer (NH4NO3) is encapsulated in the chitosan biopolymer, which is derived from a polymer derived from the shell of crustaceans, called chitin. The resulting nanospheres have a size ranging between 100 and 375 nanometers (nm).

Ledezma Delgadillo found that being of a nanostructured size, the capsules nourish the plant better. "Since the pores of the roots are small and is one of the reasons why fertilizers do not enter properly, a nanostructured size could facilitate the nutrition of the plant, thus we will reduce the use of fertilizers; For its part, chitosan does not damage the soil, in fact the same bacteria that are in the soil can take this substance as food.

Even the root of the experimental crop plant, nourished with nanospheres, had a longer length compared to the control crop plant. In this case, the experiment was conducted with lettuce in a hydroponic culture, a method where the use of the soil is replaced with a system of tubes of polyvinyl chloride (PVC) through which water recirculates, or some substrate such as coconut fiber , agrolita, vermiculite, peat, etc., in order to control the amount of mineral nutrients.

"This in the crops helps because it advances more the root and could take more nutrients from the subsoil, which are not readily available; The deeper the root, the more nutrients there are. Having a longer root, takes more nutrients and requires less fertilizer ", Agregó.

Manufacture of nanospheres

The process to obtain the nanospheres starts in a beaker, where the chitosan is dissolved in methacrylic acid (C4H6O2) for twelve hours; subsequently, at a temperature of 100 ° C, with magnetic stirring, the potassium persulfate (K65S2O2) is added as a polymerization initiator. These materials are joined by electrostatic forces and the nanocapsules are obtained, only to avoid their agglomeration they collapse with a cold bath, in addition to centrifuging them to remove any type of remnant. Finally, the nitrogenous fertilizer is added.

"In addition to reducing the use of fertilizer by 65 percent, we are in the process of verifying that chitosan, by itself, induces greater growth in the fruit"He said.

Benefits for the environment

The researcher hopes that in a few years her proposal will crystallize in the agricultural fields and thus reduce the use of fertilizer in the crops. On this, he announced that in agricultural locations it has been proven that the excessive use of these chemicals generates a great risk to health.

Such is the case of the study that was conducted in Estación Bamoa, municipality of Guasave, Sinaloa, called Impact of nitrogen fertilization on water for human consumption, where the results showed nitrate concentrations (N-NO3) well above those recommended by the Official Mexican Standard (NOM), which is 10 milligrams per liter and in this community were found up to 22.7 milligrams per liter.

Nitrogen fertilizers seep into groundwater and aquifers is so severe that prolonged consumption of these waters can cause cancer, in addition to spontaneous abortions and a disease called methemoglobinemia, which inhibits the transport of oxygen in the blood, said document . Ledezma Delgadillo said that he will apply the method of encapsulation in other types of fertilizers such as phosphate or potassium.

Source: Dicyt.com