Beneficiile culturilor de acoperire asupra culturilor agricole

Culturi de acoperire: producția de biomasă și reciclarea nutrienților Studii privind efectul rotației și asolamentelor asupra solului Studii privind efectul rotației și fertilizării asupra culturilor de acoperire Efectul culturilor de acoperire asupra producției culturilo

USE OF PROTEIN HYDROLYSATES IN ORGANIC AGRICULTURE

It is known to be a real challenge to find sustainable alternatives for the use of mineral fertilizers, especially nitrogen-based ones. This is a legal requirement in organic farming. Organic sources have a low concentration of nitrogen but have the advantage that they come from a renewable source and are found along with other compounds that have positive effects on plant nutrition. Protein hydrolysates(PHs) can improve agricultural production in terms of quality and quantity by enhancing seed germination, root development and nutrient uptake and can reduce the amount of chemical fertilizers used. This paper presents data from the literature on the use of protein hydrolysates as a source of nitrogen for crop fertilization

Influence of four foliar fertilizers on the quality and quantity of the production of Cabernet sauvignon grapes in the context of iron chlorosis

The quantity and quality of the grape crop in the conditions of iron deficiency may be significantly improved by the use of foliar fertilizers. Among the four types of foliar fertilizers, the best results in mitigating the effects of iron deficiency were attained by the fertilizers which, in addition to a complex mineral composition, also had a content of organic matter in the form of humic acids (V4) or protein hydrolysate (V5). The differences show that the organic elements have a stimulating influence on the plant metabolism and that the iron alone or even a complex foliar fertilizer with micro and macro-elements has a smaller impact on the crop (in terms of both quality and quantity) than the mineralorganic combinations. Moreover, a less favourable aspect can also be noticed, namely the fact that the fertilizers with an organic content contributed to a larger extent to the increase of the total nitrogen content in the grape, possibly influencing the wine clarification process

Protein hydrolysates and amino-acids fertilizers – physicochemical characteristics

The necessities of a sustainable agriculture require the use of fertilizing solutions and methods capable to respond to the needs of agricultural crops and to the requirements of the environment protection. In this regard, extra-radicular fertilizers and liquid fertilizers with application or incorporation into the soil respond to these priorities. In the past 20 years, the range of fertilizers has greatly diversified, currently being developed the compositions containing minerals together with natural or synthetic organic substances, with application to a wide range of crops. Organic substances added are intended to stimulate the activity of photosynthesis, absorption of nutrients, to provide a balanced nutrition, to combat nutritional deficiencies and reduce the effects of different stressors. The most frequently used organic substances are protein hydrolysates of plant or animal origin, and various amino-acids. Complex matrices resulted by including into NPK structures organic substances led to the development of new types of bio-fertilizers whose agrochemical effects were tested with positive effects on the nutrition of different crops in the conditions present in Romania. Through a careful selection of raw materials and technological processes, certain formulas of bio-fertilizers can be used in organic farming, where the imposed requirements are defined by European regulations and verified by certification bodies. In my own researches the concerns are directed towards producing these fertilizers and their testing in the vegetation/green house and in field. This paper shows the physical and chemical characteristics for some of the complex matrices with organic substances used in agriculture

Recultivation of slag heaps by fertilization with organic fertilizers

By the application of the new liquid fertilizer AH-I 100 l/ha at the first alfalfa crop (2011), the values of mobile phosphorus content in the soil increased to 64.15 mg/kg as compared to the non-fertilized control of 51.17 mg/kg. By the increase of the AH-I liquid fertilizer dose to 150 l/ha, the mobile phosphorus content in the soil increased as compared to the non-fertilized control to the value of 68.47 mg/kg due to the fertilizer which contains NPK in its matrix. Upon application of 100 l/ha AH-N, the mobile phosphorus content in the soil increases to 164 mg/kg as compares to the non-fertilized control, whose content is 152 mg/kg. Following the application of the treatment with AH-I in one dose at the second crop, significant increases of the mobile phosphorus content in the soil were noticed, i.e. 77.51 mg/kg as compared to 5349 mg/kg in the non-fertilized witness. AH-N applied in one dose (100 l/ha) obviously increases the mobile phosphorus content in the soil to 180,20 mg/kg as compared to 154 mg/kg in the non-fertilized control. The increase of the AH-N dose (150 l/ha) resulted in an increased mobile phosphorus content up to 189 mg/kg as compared to 154 mg/kg in the non-fertilized control. The applied treatments did not change the total nitrogen content in the soil

Research regarding bioremediation of the soil polluted with petroleum hydrocarbons, in the green house

On the background where no absorbent was used, the highest rate of degradation of the petroleum hydrocarbons (47%) was attained in the variants treated with the AH-SH fertilizer, the highest rate of degradation of the hydrocarbons (45%) on a background without absorbent was attained in the variants treated with potassium humate and microelements along with the bacterial inoculant. Upon utilization of 16 t/ha peat as absorbent without using any microbial inoculant, the highest rate of degradation (43%) of the petroleum hydrocarbons was attained following the fertilization with AH-SG1, upon application of the bacterial inoculant, the highest rate of degradation of the petroleum hydrocarbons (47%) was provided by fertilization with AH-SG2. Upon application of a 16 kg/ha dose of Zeba absorbent without any bacterial inoculant, the highest rate of degradation (47%) of the petroleum hydrocarbons, 45 days after the application of the treatments, was provided by the fertilizer AH-SG2. Upon treatment with 16 kg/ha Zeba absorbent and application of the bacterial inoculant, the highest rate of degradation (52%) was provided by the fertilizer AH-SG1. The second highest rate of degradation, 51%, was provided by the fertilizer AH-SG1. Upon application of 32 kg/ha Zeba absorbent without any bacterial inoculant, the best results in the bioremediation process were obtained following the treatment with the fertilizer AH-SG2 in a dose of 650 l/ha plus 64 kg/ha glucose. In these variants, the level of the petroleum hydrocarbons dropped by 59% after just 45 days of treatment or 60 days after the pollution. Upon application of 32 kg/ha Zeba absorbent along with the bacterial inoculant, the highest rate of degradation of the petroleum hydrocarbons (54%) was provided by the fertilizer AH-SG1. The second highest rate – 53% – was provided by the fertilizer AH-SG2

OBTAINING AND TESTING OF FERTILIZERS WITH ORGANIC SUBSTANCES

Due to legislation for environmental protection and the need to obtain products "cleaner" worldwide there is a major trend of development both the research and the production of fertilizers with organic substances with growth stimulating effect for use for intensive and organic agriculture (especially for protection of crops, and prevent and combat nutritional deficiencies).Approaching the concept of fertilizers containing substances of category biostimulators is a difficult task by the fact that describing the concept of biostimulants is far from being completely understood and legislation, research and experimentation are, regarding this category of products used in agriculture, at an early stage of development.This paper presents a range of NPK fertilizers with organic substances represented by protein hydrolysates and extracts from algae, with primary and secondary nutrients and physical and chemical characteristics of fertilizers obtained experimentally. These fertilizers were tested in the national network of testing of fertilizers in order of authorization for use in agriculture. It was observed that the combination of fertilizer is well assimilated by plants, with a synergistic effect of growth and protection against diseases and pests.If the application of these fertilizers were obtained yield increases between 25-30% for the tomato crop and 27 - 32.5% for the apple, as well as changes in photosynthesis process marked by increases of 30-37% of assimilating pigments

Variability of the PH and of the content of iron assimilable from the soil in the context of the presence of bicarbonates

In order to study the effect of various species of bicarbonates on the pH and on the content of DTPA-extractable iron, an experiment was organized, showing the effect of 7 progressive concentrations (from 0 to 3%) of ammonium, sodium and potassium bicarbonates. The results show the progressive increase of the pH proportionally to the concentration of bicarbonate ion, as well as an initial decrease and then an increase of the extractable iron content. The pH of the soil in the experiment is 5.44 and its DTPA-extractable iron content is 158 mg/kg; following the addition of the bicarbonates, the pH increases up to about 10 in the case of the sodium and potassium bicarbonates and up to 8.5 in the case of the ammonium, while the extractable iron decreases to about 100 mg/kg and then it increases to about 680 mg/kg in case to the sodium, 176 mg/kg in case of the potassium and 130 mg/kg in case of the ammoniu