Biological indices of soil organic matter in long term fertilization experiment

Dynamics of labile fractions of soil organic matter under 36-years of application of mineral and organic fertilizer in Chernozem (Mollisol) in Ukraine were studied. "Light" fractions of SOM between various mineral and organic fertilization treatments were studied. Amount of total organic C increased in manured treatments; while amount of total N didn't change under any of the treatments. Labile N was correlated to soil mineral N, MBC and MBN, LFN and LFC, while labile C correlated to the total organic C, LFC and LFN. The pattern of mineralization and accumulation of SOM suggested that OC dynamics more related to long-term substrate addition, while N dynamics better reflects short-term substrate addition. Application of mineral fertilizer alone accelerated mineralization of SOM, especially of "light" fraction, while partial or complete replacement of inorganic by organic fertilizers has a significant impact on soil microbial community and soil capability to supply plants with nutrients for longer period

The effect of the application of complex and mixed fertilizers on wheat yield and soil fertility

Crop productivity and soil fertility of arable lands largely depends on the applied fertilizer, including their composition, dosage and way of application. In the paper, a comparison of the fertilization values of different composite fertilizers was performed. The complex composite and different mixed fertilizers with fillers (lime and zeolite) were used in two experiments on two types of soil, Pseudogley and Cambisol. The grown crops were wheat and corn. The results showed no significant differences between applied fertilizers in terms of crop yield and nutrient uptake. Use of lime and zeolite as filler didn't result in increase of the fertilization effect of the applied fertilizers. The way of distribution of composite fertilizers influenced on the overall fertilization effect. Manual application of mixed fertilizers had better fertilization effect in comparison to mechanical spread, while use of complex fertilizers mechanically had better effect in comparison to blended mixed fertilizers

Fractionation of soil phosphorus in a long-term phosphate fertilization

The changes in inorganic and organic phosphorus (P) fractions of soil resulting from long-term fertilization (40 years) were investigated. In order to improve understanding of the sink and sources of phosphorus, P-fractions were extracted from soil samples of 0-30 and 30-60 cm depth with different amounts of monoammonium-phosphate (MAP) and then determined. Stagnosol was the type of the studied soil. Phosphate fertilizer was applied in 26, 39 and 52 kgP/ha amounts during the period of 40 years. Samples were subjected to sequential extraction according to the modified Chang and Jackson method and BCR (Community Bureau of Reference) sequential extraction procedure in order to extract different forms of phosphorus. The Certified Reference material CRM 684 (River Sediment Extractable Phosphorus) was used to provide accuracy of the instrument and both used methods. Furthermore, the association of phosphorus with substrates was provided by comparison of the results of sequential methods of phosphorus species with the sequential extraction of metals (Fe, Al, Mn and Ca). Results of continuous fertilization during 40 years indicated the increase of all the phosphorus forms in the soil except of phosphorus bound to calcium and organic phosphorus. Application of higher amounts of P-fertilizer resulted in dominance of Al-P fraction in studied soil which indicated that this fraction was the most responsible for the migration of phosphorus along the soil profile

Soil acidification as a limiting factor to agricultural production in the municipality of Ljubovija

The process of soil acidification means, above all, a reduction of soil solution pH. It can be the result of slow, years-long natural process or considerably accelerated due to a combination of natural processes and anthropogenic influences. Acidification is a very important factor in the permanent degradation of the fertility of soil, as the most important and hardly renewable natural resource. Studies on soil susceptibility to the process of acidification were carried out in the Municipality of Ljubovija, using three methods. Defining of the degree of soil susceptibility to the process of acidification allows timely activities aimed at the reduction of overall soil acidity. Management of agricultural land, in isolated areas, must be focused on a balanced use of fertilizers and agrotechnical measures, using proper planting /crops to achieve the optimum use of resources and sustainable soil fertility

Measurement of hydraulic properties of growing media with the HYPROP system

Knowledge of hydro-physical properties is an essential prerequisite for assessing the suitability and quality of growing media. The method used for sample preparation is important for the measurement results. Three different sample preparation methods were compared. The methods differed in terms of the way the 250°cm3 steel cylinder was filled and the height of preloading. Measurements on loosely filled cylinders were included. The comparison was carried out on 15 growing media using the HYPROP device. HYPROP enables a complex analysis of the hydro-physical properties with high accuracy and reproducibility. The water retention curve, the unsaturated hydraulic conductivity function, the dry bulk density, the shrinkage and the rewetting properties can be measured simultaneously. The air capacity and the amount of plant-available water in pots depend on the height of the pot. In the field, it is related to the field capacity. The quality assessment was carried out both for flowerpots of different height and for field conditions with free drainage. Loosely filled samples consolidated hydraulically shortly after the start of the measurement. These geometric changes can be taken into account with the HYPROP. The sample preparation method – preloading or loose filling – yielded significantly different results for the pore volume, dry bulk density, plant available water and air capacity. The total pore volume of the loosely filled cylinders varied between 86.8 and 95.2°% by vol. (preloaded 81.3 and 87.7°% by vol.). The most critical factor was the air capacity. Loosely filled substrate samples achieved the highest air capacities, but also did not reach the critical value of 10°% by volume in shallow flowerpots, e.g. in 10 cm pots with 5.8°% by volume. The sample preparation method, measurement and quality assessment of the hydro-physical properties of growing media should be adapted to the conditions of use – whether they are used in a field with free drainage or in pots or containers in greenhouses

Frakcionisanje fosfora u zemljištu nakon dugotrajne primene fosfornog đubriva

The changes in inorganic and organic phosphorus (P) fractions of soil resulting from long-term fertilization (40 years) were investigated. In order to improve understanding of the sink and sources of phosphorus, P-fractions were extracted from soil samples from depths of 0-30 and 30-60 cm with different amounts of monoammonium-phosphate (MAP) and then determined. The studied soil was of the Stagnosol type. Phosphate fertilizer was applied in 26, 39 and 52 kg P ha(-1) amounts during a period of 40 years. Samples were subjected to sequential extraction according to a modified Chang and Jackson method and the Community Bureau of Reference (BCR) sequential extraction procedure in order to extract different forms of phosphorus. The certified reference material CRM 684 (river sediment extractable phosphorus) was used to confirm the accuracy of the instrument and of both employed methods. Furthermore, the association of phosphorus with substrates was provided by comparison of the results of sequential methods of phosphorus species with the sequential extraction of metals (Fe, Al, Mn and Ca). The results of continuous fertilization during 40 years indicated increases of all forms phosphorus in the soil except of phosphorus bound to calcium and organic phosphorus. Application of higher amounts of P-fertilizer resulted in the dominance of the Al P fraction in the studied soil, which indicated that this fraction was the most responsible for the migration of phosphorus along the soil profile.U ovom radu ispitivane su promene u frakcijama neorganskog i organskog fosfora (P) u zemljištu koje su izazvane 40 godišnjim đubrenjem amonijum-fosfatom (MAR). Đubrivo je dodavano u količinama od 26, 39 i 52 kg P po hektaru zemljišta. U cilju praćenja mobilnosti fosfora, ekstrahovane su fosforne frakcije sa dve različite dubine zemljišta: površinski sloj od 0-30 cm i dubina od 30-60 cm. Tip ispitivanog zemljišta je Stagnosol. Uzorci su u cilju ekstrahovanja različitih oblika fosfora podvrgnuti sekvencijalnoj ekstrakciji i to na dva načina: prema modifikovanoj Chang i Jackson metodi i BCR metodi. Sertifikovani referentni materijal CRM 684 (rečni sediment) je korišćen za praćenje tačnosti obe korišćene metode. Osim toga je proučeno vezivanje fosfora sa supstratima (Fe, Al, Mn i Ca) koji su ekstrahovani sekvencijalnom ekstrakcijom metala. Rezultati ukazuju da kontinualno 40 godišnje đubrenje dovodi do povećanja sadržaja svih oblika fosfora u zemljištu osim fosfora koji je vezan za kalcijum i organskog fosfora. Primenom veće količine fosfornog đubriva dolazi do dominacije frakcije fosfora vezanog za aluminijum u ispitivanom zemljištu što ukazuje da je ta frakcija najodgovornija za migraciju fosfora kroz zemljište