Influence of Long Term Fertilization With NPK on Wheat Production and Chemical Characteristics of Typical Chernozem From Valu Lui Traian

To determine the evolution soil fertility as a result of NPK fertilization, are presented experimental results from a long-term experience after 44 years of fertilization. The experimental field is located on the chernozem - soil type, the plant of culture was wheat. Nitrogen and phosphorus doses that were applied had 2 graduations. We tracked the influence of fertilizers on the production and content of nitrogen, phosphorus, potassium, humus, pH and heavy metals: Cu, Cd, Pb and Zn from the soil after harvesting. The highest yield (4288 kg / ha) was obtained in fertilized variants with N100K150, variants where the production level increased by 216% compared to the unfertilized soil (1987 kg / ha); Fertilization with 100 kg / ha of phosphorus alone or with 50-150 kg / ha of potassium and fertilization with N100P100 along with doses of 50-150 kg / ha of potassium have led to very significant increases in the level of the mobile phosphorus in soil (from 34 mg / kg in unfertilized soil to 178 mg / kg in variant fertilized with N100P100 kg / ha), the potassium content of the soil increased very significantly with the increase of the applied potassium dose

LONG TERM NITROGEN AND PHOSPHORUS FERTILIZATION INFLUENCE UPON SOIL

The paper presents the results obtained in the SCDA Secuieni long term experimental field. The effect of long term (42 years) nitrogen and phosphorus fertilization upon soil fertility and yield was followed up with 0, 40, 80, 120, and 160 kg N/ha and 0, 40, 80, 120, 160 kg P/ha doses. Long term fertilization led to a statistically significant increase of grain yield. Harvest increased from 5,569 kg/ha in the unfertilized control to 9,805 kg/ha in the N160P160 fertilized variants. Each kilogram of phosphorus brought a 6.78 kg corn grain gain, and for each kilogram of nitrogen a 15.28 kg corn grain increase was obtained. Phosphorus long term fertilization significantly increased the total and mobile soil phosphorus content: from 0.0160% in the unfertilized control to 0.094% in the variants fertilized with 160 kg P/ha, respectively from 8 mg PAL/kg in the unfertilized control to 144 mg PAL/kg in the variants fertilized with 160 kg P/ha, and didn`t significantly change total and mobile potassium level. No significant humus and nitrogen levels modifications occur under the influence of nitrogen and phosphorus long term fertilization

MINERAL FERTILIZATION BY APPLYING OPTIMUM NITROGEN DOSES AT FARM LEVEL

An important measure included in the Code of Agricultural Practices is related to the standards on maximum quantities of nitrogen fertilizers which may be applied on agricultural lands in order to prevent or reduce nitrates pollution of water bodies. For this, fertilizer plans at farm level are reccomended to be carried out. The case study is accomplished within a farm located in Ialomita watershed. This paper shows a fertilization plan obtained by using best practices for efficiently nitrogen use at farm level. Different indicators were needed: expected crop yield at farm level, soil indicators and coefficients of nitrogen use. As much the difference between applied applied nitrogen and exported nitrogen is lower within the farm, as much the nitrogen use efficiency is higher. In case of wheat, the optimum economic nitrogen dose recommended for obtaining 8000 kg/ha is 138 kg/ha of nitrogen. This dose is correlated with the optimum soil nitrogen supply, plant nitrogen need and the lower risk of nitrogen losses in water bodies

THE NEED FOR CHALKING AND CHEMICAL FERTILIZERS APPLICATION ON THE ALBOTA ALBIC LUVISOL

A field experiment was carried out at SCDA Pitești, on an Albic Luvisol with a 25.0-25.2% clay content, with soy crop, Raluca TD variety. Seeds were treated with Bradyrhizobiumjaponicum, the density was 45-50 germinable grains/m2, and the distance between rows 50 cm. Fertilizers were applied during the vegetation cycle as follows: Dual 1 liter/ha, Décor 0,5 liters/ha, and Pulsar 1 liter/ha. The experimental design included 12 variants with the following chemical fertilizers doses: N0P0, N40P40, and N80P80. Agrocalcium (a product obtained by lime fine grinding, with a minimum 90% calcium carbonate content) and Doloflor (100% BIO fertilizer based on bitter spar with a minimum 50% calcium and magnesium oxide content) were used as chalking. Doloflor application as powder and granules in a 2.5 t/ha dose without N and P fertilization modified the soil reaction and pH registered values of 5.3-5.5, in the moderately acid reaction domain. Doloflor powder and granules in 2.5 t/ha dose together with N40P40 and N80P80 fertilizers doses determined very high mobile phosphorus content values (95-97 mg/kg). Mobile potassium contents in the analyzed variants are low ((100-125 mg/kg). Grain yield ranged from 1,483 to 2,053 kg/ha. The lowest yield resulted in the unfertilized and unlimed control. The highest values of grain yield were obtained when applying liming doses together with complex fertilizers

THE RESEARCH FOR THE DEVELOPMENT OF AGRICULTURAL RECOVERY TECHNOLOGY OF STERILE LANDFILLS RESULTING FROM THE CURRENT EXPLOITATION OF LIGNITE

The research was organized on the Balta Unchiașului tailings dump, Rovinari, Gorj county, a dump covered with 30 cm of fertile soil, aiming to establish the effect of fertilization with fertilizers, cattle manure, compost, lignite –based fertilizer and liquid fertilizer based on humates extracted from lignite on sunflower production and followed the effect of fertilization with mineral fertilizers, manure, compost and liquid fertilizers based on humates extracted from lignite, on the sunflower crop). The chemical characteristics of the crop substrate had a large variability and consisted of: pH values between 8.08 and 8.35, so a slightly alkaline reaction, humus values between 2.50 -3.52%, being valued as a low-medium level of supply, the level of nitrogen total between 0.101 and 1.60%, therefore a low-medium level of supply, mobile phosphorus between 25 and 44 mg/kg, therefore a medium-high level of supply. The most high values is recorded in the variants fertilized with manure and compost, mobile potassium between 152 and 315 mg/kg, so a medium - high supply level, copper between 18 and 23 mg/kg, so normal supply values, nickel between 30 and 37 mg/kg, so an average load, lead between 7 and 12 mg/kg, values that highlight a normal level of load, manganese between 473 and 595 mg/kg, so normal values, zinc between 48 and 66 mg/ kg, showing normal values and cadmium 0.17 AND 0.32 mg/kg so normal values. The sunflower plants can be used as copper hyperaccumulators

Soil phosphorus and potassium solubilization in an experiment with field crops in the Great Brăila Island

Along with nitrogen, phosphorus and potassium are the most important nutrition elements for plants; they are to be found in all their organs, are components of the needed substances for vital processes, and have important roles in many biochemical reactions. Accessible fractions for plant nutrition are but small fractions of the total phosphorus and potassium soil contents. The influence of soil reaction (pH), humus content, and total forms upon phosphorus and potassium solubilization in the ammonium acetate lactate solution at pH 3.7, down to a 50 cm soil depth, was studied in an agro-chemical experiment carried out in six farms of the Great Brăila Island, with seven field crops diversely fertilized with nitrogen, phosphorus, sulphur, and – for only one of the crops and in small quantities – potassium; phosphorus available contents for plants were also computed as in neutral – slightly alkaline soils as it is the case they are not the same with the contents analytically determined in the used extractant. Phosphorus and potassium solubilization degrees were very significantly influenced by soil reaction and in the case of potassium by the organic matter content too. Because of the neutral – slightly alkaline soil reaction phosphorus soluble in the ammonium acetate lactate solution and the one available for plants, found out by computing, were differently influenced. Effects registered under each crop were very significant for phosphorus and less for potassium following the diverse fertilization systems

Efficiency of foliar fertilization on wheat production in conventional and conservation agriculture

The paper presents the leaves fertilization influence upon wheat yield in two experiments carried out in conventional agriculture and conservative systems. The experimental fields comprised 6 leaves fertilizers variants and a control and were laid out at SCDA Teleorman on a Haplic Phaeozem. Two treatments were applied with 1.25% leaves fertilizer on a N90P40K0 agrochemical background proceeded from a complex 20-20-0 fertilizer, in the autumn, before sowing, and 50 kg N/ha Nitrocalcar, applied in the spring. Leaves fertilization, applied in the conservative system experiment, didn’t bring forth a significant yield increase as compared to the control. Significant and distinctly significant increases of the wheat yield were obtained in the conventional agriculture system, from 5,795 kg/ha in the control up to 7,373 kg/ha in the Nutrifert S variant. The average conventional agriculture yield (6,978 kg/ha) was higher than the conservative agriculture one (5,457 kg/ha) by 27.8%