New types of organo-mineral fertilizers, production technologies and agronomic and agrochemical efficiency

Transcription

1 Summary of the doctoral thesis on the subject New types of organo-mineral fertilizers, production technologies and agronomic and agrochemical efficiency In the last 150 years, in the agricultural experience, the use of fertilizers has enlarged due to the results obtained in quantity growth, but also in the qualitative growth of crops, at the same time with the need for insuring an even larger need for aliments as a result of the demigraphic growth. In the beginning, choosing the type of fertilizer and the used quantity was empirical, without being based on an analysis of the way to be used, and of the conditions needed for obtaining a maximum economical efficiency and improvement of the quality of products. During this entire period the development of the technologies for producing chemical fertilizers has had a conflicting nature. Thus, between the year 1831 (the obtaining of the first phosphor fertilizers) and 1921 (when in the USA they started applying the haber process for obtaining ammonia) the development rythm of this industry was a slow one, with simple technologies that used as raw materials mainly waste/ secondary products of other industries. In the following period, until the year 1950, although they has set the basis for the ammonia synthesis and after that for the nitrogen fertilizers, this stage has been more a kind of mixture and manipulation of materials and unitary products, than a chemical industry in its own with processes and unitary technologies. Starting with the year 1950, by developing the projection and research activities, begins the period for diversification and continuous growth of the importance of the chemical industry as one of the major places in the development of world-wide industry. After the year 1960, a major characteristic of the period is the tendency to integrate the fertilizers industry, due at the begining to the need for optimization and growth of the economical efficiency of fabrication processes, and also diversification of the product range. A main factor of this period was represented by the appearance of petrochemical societies and concerns that insured both raw materials (natural gas, petroleum products, coal) and also their processing technologies until obtaining chemical fertilizers as finite products. Nowadays, the types of chemical fertilizers used mainly in the countryes with a developed industry and agriculture are the classic, traditional ones, also used in the last twothree decades. A special characteristic is represented by the request for fertilizers with a high content of active substance, with or without mezzo or microelements. According to the evaluations present on the fertilizers market, doubling the content of active substance in the chemical fertilizers leads to economies of at least USD/t chemical fertilizers, due to the reduction of costs on the unit of active substance applied, of the transport costs, storage

2 and application. Also, in the last years, a great attention is being paid to the growth of the release and assimilation degree of the nutrients in the applied chemical fertilizers. Establishing the nutrition regime of plants represents a prerogative both form the point of view of applicable maximum or minimum concentrations of the fertilizers, of the application conditions of nutrient elements, and also from the point of view of the evaluation of fertilizers doses that would ensure the best nutrition and development of plants. A major tendency in the structure and yield of chemical fertilizers outlined in the last 35 years is represented by the increase and diversification of the range of liquid fertilizers, and also water soluble ones, regardless of the technologies of use and application in agriculture. The methods for application and assimilation of the liquid fertilizers by the plant have led to a conventional separation into liquid fertilizers with extraradicular application, by absorbtion into the soil (after or at the same time with the works for its preparation), by injection into the soil, irrigation, spraying, watering by dripping and respectively fertilizers with folliar application, but the term extraradicular being more precise. The results obtained by extraradicular application cannot be totally separated from those obtained by using the fertilization method with spraying systems. The use and diversification of the range of liquid fertilizers, extraradicular and of the new application technologies, is a policy toward the reduction of the degree of fertilization with classic fertilizers and implicitely that of the pollution of the soil and of the water table by their administration, and thus situating itself in the European rules for protection of the environment and promoting a modern, efficient and less polluted agriculture. The rapid development of fertilization methods and technologies by using extraradicular and liquid fertilizers is due both to the possibilities of their controlled application depending on the vegetation stages, crop, agrofond and nutrition deficiencies, and also to the growth of the efficiency of indicators regarding fertilization costs economical results. The composition of such fertilizers has to be selected as to offer the necessary quantity of macro, mezzo and microelements both as supplementary fertilizary, and also for treating and equilibrating the stress situations determined by the growth of the consumption of nutritious substances during the internal development phase of the plant ( peak of the gestation), or of the unfavourable conditiond determined by temperature or technological factoris, agrofond.in this context, the composition of the fertilizer is determinant in realizing the quantity and quality parameters of the crop, especially in the case of intensive field crop, in glass houses and solars. The research activities undertaken for the elaboration of the PhD thesis aimed at obtaining new fertilizers with complex structures containing macro-nutrients, mid and micro-elements which were enriched with natural organic substances of animal origin (protein hydrolyses) or of vegetable origin (fulvic and humic substances), fertilizers with radicular or extra-radicular application. The research took place within and had as main objectives:

3 - identification of the main trends and perspectives regarding the creation and the evolution of liquid complex fertilizers and especially of those with extra-radicular application containing natural organic substances having bio-stimulating effects; - creation of new structures of fertilizers with radicular or extra-radicular application characterized by a complex matrix of NPK-type with mid, micro-elements and natural organic substances of animal or vegetable origin having chelating and biostimulating properties; - elaboration of the technologies for obtaining the technological schemes and mass balances at laboratory and productive pilot stage; - obtaining samples of fertilizers and the physical and chemical description for agrochemical tests on different cultures; - agrochemical testing of the new fertilizers in the conservatory house of vegetation experimental field, demonstration lot and greenhouse; - physical and chemical analysis and also microbiological analysis of soil, plants, seeds, grains and fruits samples; - processing, using statistic methods, of the biometric results obtained and of those given by chemical analysis; - dissemination of the results obtained, by participating in national and international events, round-tables, work visits, exhibitions, fairs, publication of scientific articles in specialized magazines, I.N.C.D.P.A.P.M ICPA Bucharest web page, and also applying for patents for the fertilizing structures elaborated within the PhD thesis. The results published in this PhD thesis were obtained by applying instruments and methods specific to statistic analysis. The research activity undertaken for achieving the objectives proposed within the PhD thesis was focused on four main themes, the results obtained for each of them being structured within four chapters. Chapter 1 approaches the following issues: - presentation of the evolution of chemical fertilizers in general, and of liquid fertilizers in particular; - policies and objectives in the present development of the chemical fertilizers industry; - classification of the mineral chemical fertilizers, classical fertilizers (azoth-based fertilizers, phosphorus fertilizers, potassium fertilizers, complex and mixed fertilizers); - emergence and development of liquid or suspension fertilizers, their classification, advantages and disadvantages; - technological solutions and procedures for obtaining liquid and suspension fertilizers; - incorporation of the secondary elements and of micro-elements in liquid or suspension fertilizers and their characterization; - fertilizers with extra-radicular application, characteristics and obtaining procedures; - fertilizers with organic substances of animal or vegetable origin; - characterization of the natural sources of humic, organic substances;

4 - dissociation and characterization of the humic and fulvic substances obtained from carboniferous mass; - methods of statistic processing of the experimental data used within the thesis; The chapter contains 22 tables and 12 figures. At international level, there is an increasing interest in the creation of fertilizers which contain natural or synthesis substances included in the bio-stimulators category, such as: heteroauxin, the beta-indoleacetic acid, tri-iodine benzoic acid, giberelin and its derivates, the amino acids, vitamins, peptides, ureides, phosphoproteins, proteic hydrolysates, seaweed extracts and also fulvic/humic acids. These substances, in low concentrations, sometimes even to ppm-s, lead both to the growth of the radicular system, of the foliar surface, of the new vegetable formations, to the development of the flowers and fruits, to their protection under climatic / technological stress conditions, and also to the development of the microbiological activities at the plant s rhisosphere area. Chapter 2 is focused on the formulation and obtaining of new extra-radicular fertilizers of NPK-type with mid and micro-elements containing collagen hydrolysate as organic substance and it approaches the following issues: - Grafting the components with chelating and bio-stimulating role (fractions of proteins with variable mid molecular mass) on a complex NPK matrix set up of macro and micro-elements; - Selection and elaboration of their composition according to: the compatibility and stability data of the proteic compounds deriving from the controlled hydrolysis of collagen, in a NPK-type matrix with / without micro-elements; the tests of physical and chemical stability, chelating capacity, film-forming and protection properties; - Setting up the operation schemes and establishing the process conditions selected for obtaining variants of fertilizers of organic-mineral type, with proteic substances; - Elaborating the lab-level technologies for obtaining the structures of the fertilizers containing hydrolysates, of the macro, mid and micro-elements matrix (technological and operation flow, component verification, technological parameters, specific consumptions); - Characterization of the bio-fertilizers obtained, from the composition point of view; - Obtaining samples of fertilizers for agrochemical tests; - Carrying out agrochemical researches in the glass-house and on the experimental field on wheat, sun-flower, soya and tomato cultures; - quantitative and qualitative characterization of the yield and statistical processing of the experimental data. The use of proteic substances, like the collagen hydrolysate, containing proteins, protides and free amino-acids with chelating properties, within a complex matrix with macro and micro-elements, provided fertilizers solutions, stabile from the physical and chemical point of view. Besides the chelating properties, the proteic hydrolysate used also serves as a protective colloid, which helps at maintaining the stability of the fertilizer.

5 The wheat, soya, sun-flower and tomato cultures reacted positively to the extraradicular fertilizers, out of which the best were those having the collagen hydrolysate grafted on the NPK structure. The use of some structures of the collagen hydrolysate type on a NPK matrix with mid and micro-elements significantly increased the yield for all cultures, compared to the classic matrices of NPK-type with micro-elements, and also higher values of the MMB and MH indicators. The chapter contains 57 tables and 27 figures. Chapter 3 aims at obtaining new compositional formulas and complex fertilizing solutions that contain protein organic substances with chelate and bio stimulating properties applied both in classic and ecological agriculture. The experimental activities realized have led to obtaining several variants of technological processes and fertilizers compound, of which 4 new structures are presented in this chapter. The principles applied for establishing the used raw materials and for defining the technological processes for obtaining these fertilizers have been specific for the ecological agriculture standards, namely The CE Regulation regarding the ecological production and labeling of the ecological products, Regulation (CE) 889/2008 for establishing the detailed rules for the application of Regulation (CE) nr. 834/2007 of the Council regarding the ecological production and labeling of the ecological products, and regulation (CE) 2003/2003 regarding fertilizers, that is referred to in the Annex I of the Regulation (CE) 834/2007. As a result of experimental activities that took place in the lab, we have established the technological processes for obtaining three compositional ranges for fertilizers, of the type: - with protein substances, NPK macronutrients and microelements, matrix constituents; - with protein substances, NK and microelements; - with protein substances and microelements. For the three fertilizing structures we have defined the technological schemes for obtaining them, we have established the operation parameters and we have elaborated the material balances. The fertilizers obtained experimentally and the protein structures have been characterized as a physical-chemical complex by using techniques like the thermo gravimetric analysis and FT-IR spectroscopy, and were also tested agro chemically. The agrochemical experiments were made in the house of vegetation, in Mitscherlich vegetation pots, on sun flower, soy, tomato and corn crops. The agrochemical testing was made comparatively with two fertilizers certified for use in the ecological agriculture. The analysis of the experimental data obtained by measuring production, growth, exportation of nutrients and composition of the plant, seeds in sun flower and soy, have shown that great results were obtained by applying extraradicular the experimentally obtained fertilizers, as they not only a role of supplementary fertilization, but also a bio stimulating one. The analysis of the biometric measurements was doubled by the statistical processing of the experimental data. In order to evaluate the differences between experimental variants,

6 we have used data obtained by statistical processing using the Fischer, DL tests and the Tukey test. The chapter contains 159 charts and 95 figures. Chapter 4 is focused on the elaboration of new formulas and the obtaining of new complex organic-mineral fertilizing solutions, containing in the matrix both natural organic substances (fulvic and humic compounds) and mineral structures. The experimental attempts, both at lab-level and at productive pilot level, led to the identification of different types of technological processes and fertilizer structures, out of which 3 were selected and presented within the thesis. The experimental activities undertaken at lab and productive pilot level led to the establishment of the technological processes, the operation parameters and the material balances for obtaining three component ranges for fertilizers, of the following types: - NPK with fulvic substances and micro-elements; - NPK with humic substances and micro-elements; - NK with humic and fulvic substances and micro-elements. The three structures of experimental fertilizers obtained were characterized from the physical and chemical point of view by using techniques such as the thermo-gravimetric analysis and the FT-IR spectroscopy, and were agro-chemically tested in the conservatory at I.N.C.D.P.A.P.M. I.C.P.A Bucharest, in protected environment, on sun-flower and tomato crops, as well as in unheated greenhouses in Matca village, Galaţi county, on tomato and cucumber crops. The agro-chemical tests were comparatively made with two fertilizers attested for use in the ecological agriculture, mainly a classical fertilizer with extra-radicular application in agriculture, on an agrofond with or without basic fertilization. The analysis of the experimental data resulted from yield measurements, increments, nutrients export and plant components, namely sun-flower seeds, indicated the obtaining of valuable, significant results in case of extra-radicular application of the experimentally obtained organic-mineral fertilizers. The analysis of the biometric measurements was completed by the statistic processing of the experimental data. The data resulted from the statistic processing after applying Fischer, DL and Tukey tests were used in order to evaluate the differences between the experimental variants. The chapter contains 72 tables and 54 figures. Part of the results of the research activities developed within the thesis were laid down in three patent applications which were submitted to OSIM. The patent applications refer to fertilizing compositions, the obtaining and applying technologies.

7 The final chapter of the PhD thesis contains conclusions and recommendations regarding the results of the experimental activity developed, both theoretically and practically, the author s personal contributions and the dissemination of the results of the undertaken researches. A list of the scientific works elaborated by the author and the bibliography referring to the authors quoted in the paper is enclosed at the end of the PhD thesis.