Investigations on the change of soil chemical and biological characteristics as influenced by crop rotation and long-term fertilization in the Moldavian Plain

Investigations conducted in long-term (39 years) stationary experiments, under non-irrigated, followed the influence of different fertilizer rates on the evolution of soil agrochemical characteristics and yield obtained in main crops, placed in 2, 3 and 4 year rotations. In maize crop, placed in 5 year rotations, the mean yield obtained during 1980-2005 was of 5920 kg /ha. Rates of N100P100 have determined yield increases by 94% (3030 kg/ha) and rates of N40P40 + 30 t/ha manure resulted in a double yield, in hybrid Oana (9 %; 3180 kg/ha) compared to unfertilized. The long-term use of 3 and 4 year rotation with ameliorative plants resulted in getting yield increases by 46 - 48% (1120-1150 kg/ha) in wheat and 27 - 35% (1180 – 1530) in maize, compared to continuous crop. Annual application of rates of 80 kg/ha P2O5 determined the accumulation of a reserve of mobile phosphates in soil, comprised, according to applied nitrogen, between 47 and 66 ppm. The humus and nutrient content from soil was maintained at a supply level proper to the requirements of plant nutrition, only under 3 or 4 year rotation and in case of annual use of rates of at least N100P100 or of mean rates of mineral elements with 30 t/ha manure

The evolution of chemical and biological characteristics in Cambic Chernozem, under the influence of crop rotation, fertilizers and soil erosion

Investigations conducted at the Agricultural Research and Development Station of Podu-Iloaiei, Iaşi County, during 2004-2008, have followed the influence of different crop structures and different fertilization methods on crop yield, erosion and soil fertility. Within the experiment, the following rotation schemes have been followed: wheat and maize continuous cropping, 2-year rotation (wheat-maize), 3-year rotation (peas-wheat-maize) and 4-year rotation + reserve field cultivated with legumes and perennial grasses (alfalfa + Lolium or Sainfoin + Bromus). The use of 3 and 4 year- rotations with annual and perennial meliorate plants has resulted in yield increases of 25 – 30 % (632 – 768 kg/ha) in wheat and 24-28% (973-1161 kg/ha) in maize, as compared to continuous cropping. The fertilization of wheat and maize crops at the rate of N60P40+30 t/ha manure has determined the increase by 3.0 g/kg (17.9%) in the content of organic carbon from soil, as compared to the rate of N100P80. The use of peas-wheat-maize-sunflower rotation + reserve field grown with legumes and perennial grasses has contributed to the increase by 2.2 g/kg (13.4%) in the content of organic carbon. The use of 4-year rotation + reserve field cultivated with perennial grasses and legumes on slope lands, poor in organic matter has determined the increase by 47% in soil potential and by 34% in enzyme potential, as compared to wheat-maize rotation. On 11% slope lands, the use of soybean-wheat-maize rotation + two reserve fields cultivated with perennial grasses has determined the diminution of soil losses by erosion at 0.985 t/ha, and on 16% slope lands, peas-wheat-maize rotation + two reserve fields, cultivated with perennial grasses has determined the diminution in soil erosion at 1.371 t/ha. On 16% slope lands, the crop structure, which determined the diminution in mean soil losses by erosion until 1.371 t/ha/year included 20 % straw cereals, 20% annual legumes, 20% row crops and 40 % perennial grasses and legumes

Assessing the Soil Physiological Potential Using Pedo-Biological Diagnosis Under Minimum-Tillage System and Mineral Fertilization

The main objective of sustainable agriculture is the protection of environment and natural vegetal and soil resources. Accordingly, the objective of this research was to assess the impact of technological systems by minimum tillage on soil biological activity, using the Pedo-Biological Diagnosis of Soil Resources. Our research was conducted on haplic chernozem from Experimental Station of UASVM of Iasi, Romania, during the seasonal dynamic, to the soybean crop, on unfertilized and fertilized agrofond, using moderate mineral doses (N80P80) as average of 2009–2010 period, under minimum tillage (2x disk, paraplow, chisel) compared to conventional (plugging at 20 cm and 30 cm). In the case of soil works with chisel and paraplow without return of furrow, the Pedo-Biological Diagnosis highlights an increase of soil physiological potential, in the both variants (unfertilized and fertilized), unlike the method of alternating the depth of plugging that proved to be ineffective

ASSESSING THE ANTHROPOGENIC IMPACT ON ENVIRONMENT BY HEALTH SOIL CARD

Deterioration of soil health due to the current intensive agricultural practices for increasing the level of food production, in terms of both quality and quantity, should be a concern of major interest to the health of plants, animals, humans and environment. Soil health is the net result of the processes of preservation and degradation, depending on the biological component of soil ecosystem that affects plant and environmental health, food safety and quality. This research aimed to assess the main physical, chemical and biological indicators of soil health and the indicators of soil residual pollution in the intensive olericultural systems in transition to organic systems for ensuring a sustainable management. Our research was carried out in conventional olecultural systems of North-Eastern Romania in conversion to organic systems.The conversion intoorganic systems has reduced the effects of intensive practices, creating the premises for an optimal biological activity and production of healthier vegetables

Features of selected benchmark soils along an elevational transect of the northeastern part of the Moldavian Plateau (Romania)

Soil morphological, physical and chemical properties are described at four locations along an elevational transect in the northeastern part of the Moldavian Plateau (Romania). These data contribute to the knowledge of the soils of this area and to their classification according to the USDA-Soil Taxonomy, FAO-WRB and the SRTS-Romanian System. The soils were classified as Inceptisols, Alfisols and Mollisols, according to the USDA-Soil Taxonomy; Gleysol, Chernozem and Luvisol, according to the FAO-WRB and Gleiosol, Cernoziom, Preluvosol, Luvosol, according to the SRTS-Romanian System. The selected soils have a range of properties that represent the soilscape of the Moldavian subcarpathian plateau, characterised by a natural forest with oak as the dominant species. The selected soil parameters decreased with increasing elevation; calcium carbonate and clay leaching and accumulation are the main soil formation processes. Keywords: Inceptisols, Alfisols, Mollisols, Climosequence, Moldavian Platea

EVALUATION OF THE INTAKE OF NITRATE, NITRITE, NITROSODIETHYLAMINE AND NITROSODIMETHYLAMINE BY FOOD CONSUMPTION

The aim of the present study was the evaluation of nitrate, nitrite, nitrosodiethylamine (NDEA) and nitrosodimethylamine (NDMA) intake by food consumption. We determined concentrations of nitrates, nitrites in 102 food samples (40 meat products, 15 fermented cheese, 25 vegetables, 22 fruits) and the concentration NDEA, NDMA in 40 meat products. Nitrates and nitrites were determined using Peter-Griess method; nitrosamines were quantified by HPLC with UV detection.  We designed vegetalian, vegetarian and conventional diets of about 2500 kcal/day.  Based of the values found, we calculated the intake of nitrates, nitrites and nitrosamines. The obtained values fits to WHO’s recommendations, except for vegetalian and conventional diet, in which the nitrate content was 3,46 respectively 1,64 times higher than the acceptable daily intake (157 mg NO3-/day)

The effect of Fertec-type liquid fertilizers on the ecological protection of the environment

In this scientific paper, we have shown the apparent degrees of the efficient use of nutrients from leaf fertilizers (GAUPENICF) and the productive degrees of the efficient use of nutrients from soil reserves (GUPENsol), based on greenhouse tomato yields, obtained after applying leaf fertilizers. In our trials, we have tested the fertilization method and leaf compositions as methods of plant fertilization, for correcting and supplementing crop nutrition in greenhouses and preventing environment pollution. By applying leaf fertilizers in greenhouse tomato crops, we have obtained high yield increases and a significant diminution in the chemical pollution of the environment. The incomplete use by the crop of nutrients from applied fertilizers has determined the increase in the incidence of soil chemical pollution. However, soil fertility may be diminished by high uptakes of soil nutrients, under conditions of weak nutrient supply of soil (without basic fertilization). Therefore, we recommended the concomitant use of soil and leaf fertilization

Fertilizers with humic substances: development and characterization of new products

Fertilizers with humic substances can be used on different types of soil, as well as in technologies for improving degraded or contaminated soils and they proved effective on a wide range of cultures. Due to the variety of sources from which they can be obtained, there are many types of fertilizers containing natural biostimulating substances. This paper presents the development of a rage of complex NPK liquid fertilizers with humic substances, meso and micronutrients. The extraction processes, the humic substances separation, and the organo-mineral fertilizers technology were conducted regarding the physicochemical properties of the humic and fulvic acids in the alkaline/acidic reaction media, as well as their stability in the NPK, meso and micronutrients matrix. Two of the experimental fertilizers are physicochemically characterized and their agrochemical efficiency is shown by the results obtained in the National Fertilizers Testing Network. In the case of soil incorporation of the experimental fertilizers, the average yield increases, as compared to the unfertilized control, were ranging from 37.8% for sunflower crop to 42.3% for sugar beet cro