Showing papers in "Archives of Agronomy and Soil Science in 2004"
TL;DR: The methods used for estimating rhizodeposition of plants (carbon (C) deposition of living roots), and the results obtained for different plant species are reviewed, and a simple approach is suggested for a rough calculation of C input into the soil and for root-derived CO2 efflux from the soil.
Abstract: The methods used for estimating rhizodeposition of plants (carbon (C) deposition of living roots), and the results obtained for different plant species are reviewed. Three tracer techniques using C isotopes to quantify rhizodeposition are discussed: pulse labelling, continuous labelling, and natural 13C abundance. Only the tracer methods provided adequate results for the whole rhizodeposition. The differences in the below-ground C translocation pattern between cereals and grasses are discussed. Cereals (wheat and barley) transfer 20 – 30% of total assimilated C into the soil. Half of this amount is subsequently found in the roots and about one-third in CO2 evolved from the soil by root respiration and microbial utilization of root-borne organic substances. The remaining part of below-ground translocated C is incorporated into the soil microorganisms and soil organic matter (SOM). The portion of assimilated C allocated below the ground by cereals decreases during growth and by increasing N fertilization. P...
116 citations
TL;DR: In this paper, the effect of chemical fertilizers and organic amendments on soil chemical and microbiological properties were studied in soils receiving these amendments over a period of 3 years under tropical conditions.
Abstract: Effect of chemical fertilizers and organic amendments on soil chemical and microbiological properties were studied in soils receiving these amendments over a period of 3 years under tropical conditions. Soil organic C and total N increased in treatments receiving a combination of organic amendments and different doses of chemical fertilizers compared to soils receiving chemical fertilizers alone. Mineral N and available P in the soil were greater with the integrated use of chemical fertilizers and organic inputs. Microbial biomass C increased significantly with the combined application of chemical fertilizers and organic amendments, in comparison to soils receiving chemical fertilizers alone. Dehydrogenase and alkaline phosphatase activities also increased with the application of farmyard manure and Sesbania aculeata green manure. The results indicated that there is improvement in soil organic matter, microbial activities and crop yields due to the use of chemical fertilizers along with organic manures. S...
114 citations
TL;DR: In this paper, the influence of site gradient and management intensities on different SOM pools was investigated, based on both a site gradient as well as a gradient in management intensity, and the authors measured the decomposability of the C pool by the parameter of hot water extractable carbon.
Abstract: Basing on both a site gradient as well as a gradient in management intensities the influence of these factors on different SOM pools was investigated: (A) a very easily decomposable C pool, (B) a C pool which is related to clay fraction and representing a relatively inert pool, (C) a C pool which is not, or only loosely connected to the mineral soil part representing the intermediates between the extreme C pools (A) and (B). The decomposable C pool was measured by the parameter of hot water extractable carbon (HW-C). The clay related and not clay related SOM pools were isolated by a combined fractionation according to both particle sizes (clay fraction < 1 μm and 1 – 2 μm) and specific densities (light fraction < 1.8 g/cm3 and 1.8 – 2.0 g/cm3). Fertilization increases easily decomposable SOM pools reflected in C content of a hot water extractable SOM fraction and in mass of specific light SOM fractions but to a certain extent the C pool associated with clay minerals as well. At comparable management (fert...
54 citations
TL;DR: Inter-mating of genotypes like HW 2006, UP 2338 and HW 2016 with those belonging to HGY-HP (PBW 343 and WH 711) and HGy-LP (Raj 3765 and WH 283) would be an ideal strategy to develop the cultivars for efficient phosphorus use.
Abstract: Thirty spring wheat varieties were evaluated and classified into eight different groups on the basis of their grain yield performance and phosphorus (P) uptake using Metroglyph analysis. Significant variability was observed for grain and biomass yield, plant height, P content in grain and straw, total P uptake and phosphorus harvest index and P use efficiency traits. Varieties WH 711 and PBW 343 exhibited high grain yield as well as high P uptake (HGY-HP). WH 283 and UP 2425 with high index score of 19 and 16 respectively, constituted the high grain yield-medium P uptake (HGYMP) group. Both these varieties, though had similar grain yield of 5348 kg/ha, but WH 283 (12.64 kg/ha) utilized much lower P as compared to UP 2425 (16.94 kg/ha). Moreover, WH 283 (81.64) also showed higher values for phosphorus harvest index (PHI) than UP 2425 (67.88%). P uptake of WH 283 was comparable with that of Raj 3765 (10.78 kg/ha) and grouped into high grain yield and low P uptake (HGY-LP) group. The grain yield performance ...
49 citations
TL;DR: Carbofuran was found to be most effective for improvement of over all plant growth and fensulfothion the least in terms of pesticidal effects on chickpea plant.
Abstract: Different concentrations, viz. 5, 10 and 25 ppm of aldicarb, carbofuran, phorate fensulfothion and fenamiphos were observed for their pesticidal effects on chickpea plant in terms of various plant growth parameters such as plant length as well as weight, pod numbers, root-nodulations and chlorophyl content. Significant improvement in plant growth was noted in lower concentrations such as 5 and 10 ppm of different pesticides but 5 ppm concentration proved highly effective and non-phytotoxic. The phytotoxic effect was noted in those plants treated with 25 ppm concentration of all the pesticides. Carbofuran was found to be most effective for improvement of over all plant growth and fensulfothion the least.
42 citations
TL;DR: In this article, the results showed that more than 75% of the total iron (Fet) was associated with the crystalline and the amorphous Fe oxides, indicating a strong accumulation of free iron oxides (Fed) in concretions.
Abstract: Fe-rich concretions commonly occur in Greek soils with alternating drying and waterlogging periods. This study was conducted to characterize the iron oxides in Fe-rich concretions from the upper solum of an Alfisol with seasonal perched water table by the combination of selective dissolution and X-ray diffraction (XRD) techniques. The results showed that more than 75% of the total iron (Fet) was associated with the crystalline and the amorphous Fe oxides, indicating a strong accumulation of free iron oxides (Fed) in concretions. Amorphous iron compounds (Feo) was present at high concentrations and fluctuated with profile depth. The active Fe ratio (Feo/Fed) values that ranged from 0.35 to 0.41 reflected an association of poorly crystalline goethite with some ferrihydrite. The XRD data showed that the Fe-rich concretions consisted of quartz, feldspars, illite and gypsum. The mineralogy of iron oxides in concretions was determined by comparison of XRD patterns for dithionite-citrate-bicarbonate (DCB) treate...
30 citations
TL;DR: In this paper, the concerns for sustainable soil productivity and ecological stability in relation to the use of chemical fertilizers have become an important issue and the authors have discussed the benefits of using traditional green manures (Sesbania aculeate), organic manures and problematic weeds (Ipomoea Carnea and Gliricidia maculata).
Abstract: The concerns for sustainable soil productivity and ecological stability in relation to the use of chemical fertilizers have become an important issue. The fertilizer consumption of the nation is 74 kg/ha whereas it is 13 kg/ha in northeastern region (as high as 44.4 kg/ha in Manipur and as low as 1.7 kg/ha in Arunachal Pradesh). The marginal farmers in northeastern region are more than 60% of the farming community who are unable to use the inorganic fertilizer and hence the productivity of rice has been very poor (less than 1 tonne/ha) in the region. Organic manures are reported to enhance the fertilizer efficiency and reduce the requirement of inorganic fertilizers. Traditional green manures (Sesbania aculeate), organic manures (FYM) and problematic weeds (Ipomoea Carnea and Gliricidia maculata) may serve as alternative source of nutrients to the plants and may supplement any chemical fertilizers. Most of the green manure plants contain from 0.3 to 0.8% nitrogen (Khan et al., 2000). Integrating fertilize...
29 citations
TL;DR: In this paper, long-term experiments in Muncheberg, Braunschweig, and Livada were used to understand the complex issue of carbon sequestration in soil.
Abstract: Long-term experiments in Muncheberg, Braunschweig and Livada were used to understand the complex issue of carbon sequestration in soil. The investigations were focused on: effects of land use changes on the fate of soil organic carbon; options of agronomic practices to maintain or to increase soil organic carbon; relationships between organic fertilization and changes in soil organic carbon. The long-term observations showed that the amount of soil organic matter is primarily a function of the prevailing land use. Clearly marked differences were observed between long-term arable farming with lower and short-term with higher soil organic carbon content. Agricultural practices lead to a decrease of soil organic carbon with the result that arable soils are rather sources of carbon than sinks. The carbon sequestration potential is caused by the agronomic management to different extents. The combination of organic and mineral fertilization increased the soil organic carbon content compared to exclusive mineral...
23 citations
TL;DR: It can be concluded that castor cake should be applied at least 3 weeks before sowing of the crop and keeping the field moist for degradation of the toxicants.
Abstract: A screen house experiment was undertaken to study effect of time of application of deoiled castor cake on the yield, N and P uptake by wheat crop. The results indicate that the wheat growth decreased significantly with increasing dose of castor cake, when castor cake was applied just before sowing of wheat. When castor cake was applied 10 days before wheat sowing, the dry matter yield (DMY) of wheat increased up to 0.125% dose of castor cake and reduced thereafter. But when the castor cake was applied 20 days before wheat sowing, the DMY was at par under all the doses of castor cake and better than control indicating the degradation of the toxicants produced by the castor cake. Application of castor cake can also be helpful in reducing the cost of phosphatic fertilizer. Thus it can be concluded that castor cake should be applied at least 3 weeks before sowing of the crop and keeping the field moist for degradation of the toxicants.
21 citations
TL;DR: In this paper, the authors estimated the necessary amount of primary organic matter (POM) for preservation of the optimal SOM content in soil on basis of the results from 10 long-term field experiments at eight different locations.
Abstract: The importance of the soil organic matter (SOM) in the environmental protection, particularly its relation to the global carbon and nitrogen cycle come increasingly into the foreground. The evaluation of the influence of SOM on the environment requires the knowledge of optimal SOM content. Several authors estimated the necessary amount of primary organic matter (POM) for preservation of the optimal SOM content in soil on basis of the results from 10 long-term field experiments at eight different locations. An average demand for farmyard manure (FYM) was determined to be 10 t.ha − 1.a − 1. The difference in the organic carbon content between the unfertilized variant and the optimum fertilized variant ranged between 0.11% Corg on a sandy soil and 0.51% Corg on loess black soil. A higher level of organic fertilization brings no yield advantages and it is connected with higher N-losses. The utilization of FYM nitrogen is around 30% lower in comparison with mineral N. The reduction of the CO2 concentration in ...
19 citations
TL;DR: The inclusion of a legume in a cropping system for maintaining organic C and available N in soil and adequate P and K fertilization for arresting the depletion of available P andK content in soil are suggested.
Abstract: A field study conducted for two crop cycles of five cropping systems supplied with six nutrient combinations at the Indian Agricultural Research Institute, New Delhi indicated that the cropping systems having a legume increased organic C content over initial level by 0.02 – 0.05%, available N by 3.5 – 14.1 kg ha − 1, whereas the rice-wheat cropping system resulted in a reduction in organic C and available N over initial level by 0.05% and 1.5 kg ha − 1, respectively after 2 years of study. Rice-potato-mungbean cropping system resulted in a negative balance of available P and rice-clover cropping system had a negative balance of both available P and available K content in soil and thus call for adequate P and K fertilization. Application of P and K helped in building up their content in soil; NPK + FYM showed the highest increase in organic C, available N, available P and available K content in soil. These results suggest the inclusion of a legume in a cropping system for maintaining organic C and availabl...
TL;DR: In this paper, the advantages and problems of various crop growth approaches (simple descriptive empirical approaches, logistic growth curve, regression, neuronal network), complex plant physiological based algorithmic models (AGROSIM model family), generic crop growth model for different spatial scales from field plots up to agro-landscapes.
Abstract: Model-based estimations of yield and biomass accumulation on arable and grass lands can be a very helpful instrument to find answers concerning different scientific or practical yield and biomass questions on different spatial scales. The ideal situation both for model developers and users would certainly be to rely on scale invariant, generic growth models applicable to different questions and spatial scales with the same reliability and controlled by a definitive and widely available set of parameters. However, experience shows that this idea is hardly accomplishable in practice. The present paper discusses the advantages and problems of various crop growth approaches (simple descriptive empirical approaches, logistic growth curve, regression, neuronal network), complex plant physiological based algorithmic models (AGROSIM model family), generic crop growth model for different spatial scales from field plots up to agro-landscapes. In addition, the paper investigates into possibilities of a model transfe...
TL;DR: In this article, Urease activity (by buffer and non-buffer method) of different agro-ecosystems in alluvial soil was studied and multiple regression analysis showed that the stabilization of urease activation in the soils studied was due to an organic matter humus complex.
Abstract: Urease activity (by buffer and non-buffer method) of soils of different agro-ecosystems in alluvial soil was studied. Urease activity by buffer method records a higher value than the non-buffer method. Both the methods showed significant positive correlation (0.99**) between each other. Urease activity by both methods showed positive correlation with organic matter (0.88** and 0.89**, buffer method) and clay content (0.91** and 0.83*, non-buffer method)) of the soils. Multiple regression analysis showed that the stabilization of urease activity in the soils studied was due to an organic matter – enzyme complex. Among the organic matter humus C plays a dominating role to control the urease activity of the soils.
TL;DR: Nitrogen fertilization increased N concentration as well as N uptake by rice in both Pusa 834 and hybrid PRH 3 and use of neem coated/blended urea is recommended for rice.
Abstract: Field experiments were made on a sandy clay loam soil at the Indian Agricultural Research Institute, New Delhi to study the effect of levels and sources of nitrogen on concentration and uptake of nitrogen by a high yielding variety Pusa 834 and a hybrid PRH3 of rice. Nitrogen concentration in hybrid PRH 3 remained lower than in Pusa 834, but N uptake was significantly more in the hybrid PRH 3. Nitrogen fertilization increased N concentration as well as N uptake by rice. At 30 days after transplanting (DAT) N uptake was more in Pusa 834, but at 60 DAT and at harvest hybrid PRH 3 recorded significantly more N uptake than Pusa 834. Use of neem oil blended urea (PNGU) and neem coated urea (NCU) increased N concentration and uptake by rice in both Pusa 834 and hybrid PRH 3. Use of neem coated/blended urea is recommended for rice.
TL;DR: Karanjin, a furanoflavonoid (3-methoxy furano) is obtained from the seeds of karanja tree (Pongamia glabra Vent.), which is reported to have nitrification inhibitory properties but has been tested in few soil types.
Abstract: Karanjin, a furanoflavonoid (3-methoxy furano – 2 ′ , 3 ′ , 7, 8-flavone), is obtained from the seeds of karanja tree (Pongamia glabra Vent.), which is reported to have nitrification inhibitory properties but has been tested in few soil types. Efficiency of karanjin as a nitrification inhibitor in seven different soils of India was tested in a laboratory incubation study. The soils (800 g) were adjusted to field capacity moisture content, fertilized with urea and urea combined with karanjin at a rate of 20% of applied urea-N (100 mg kg − 1 soil) and incubated at 35°C for a period of 7 weeks, during which urea [CO(NH2)2], ammonium (NH4 + ), nitrite (NO2 − ) and nitrate (NO3 − ) content in the soils was measured periodically and nitrification inhibition at different stages was calculated. Urea hydrolysis was almost complete within 72 h of application in all the soils and was not affected by karanjin. Karanjin had conserved ammonium in all the soils at all stages and nitrate formation was effectively mini...
TL;DR: In this paper, the geomorphic features and soil formation of the arid lands in northeastern Jordan, to provide information that could be used by land managers in the study area and other arid land areas.
Abstract: Arid and semiarid lands occupy about one-third of the Earth's land surface. Interpretation of soil formation and geomorphic features of arid lands is needed to assess their soil ecological potentials, limitations, problems and management needs. The objective of this paper was to study the geomorphic features and soil formation of the arid lands in northeastern Jordan, to provide information that could be used by land managers in the study area and other arid land areas. Five representative soil pedons were excavated and described in the field. Soil samples from each horizon per pedon were taken to the laboratory for chemical and physical analyses. Geomorphic features of the area were also studied. Most of studied land surfaces are plains where eolian deflation has exposed loose gravels consisting predominantly of pebbles forming desert pavements. Desert pavements cover most of the land surface, excluding the mud playas, and are composed of basalt clasts. The accumulation of calcium carbonate and gypsum wi...
TL;DR: In this paper, the influence of different fertilization on the dynamic of C and N content in soil is presented from the Eternal Rye trial and from the long-term fertilization trial Field F founded by Julius Kuhn in 1878 and by Karl Schmalfus in 1949, respectively.
Abstract: Results about the influence of different fertilization on the dynamic of C and N content in soil are presented from the Eternal Rye trial and from the long-term fertilization trial Field F founded by Julius Kuhn in 1878 and by Karl Schmalfus in 1949, respectively. Mainly the organic (i.e. farmyard manuring and straw fertilization) but also the mineral N fertilization had a significant effect on both parameters. New steady states typical for applied fertilization treatments have been reached after decades of trial, e.g. the residual effect of 60 years of farmyard manuring on soil and plant is significant even 50 years after cessation of fertilization. Furthermore, rotation, soil, ploughing depth and atmosphere emmision influenced soil C and N turnover. The effect of fertilization was modified by even slight differences in soil characteristics. The results confirm the importance of long-term trials for management strategies in sustainable agriculture.
TL;DR: In this paper, experimental plantations were established using two ecotypes of Avicennia marina (Bahrain and UAE) and one ecotype of Aviciennia germinans (Florida).
Abstract: The State of Kuwait has initiated an ambitious national program to establish greenery in 20000 ha of open spaces in inland and coastal areas. Afforestation of intertidal zones with mangrove plants is being considered as a viable option for greening coastal areas. In view of this fact, experimental plantations were established using two ecotypes of Avicennia marina (Bahrain and UAE) and one ecotype of Avicennia germinans (Florida). The study consisted of two 10-year old plantations and two 2-year old plantations. Seedlings established successfully and grew vigorously on some of the locations within the site. Therefore, studies were conducted during 2002-2003 to describe and classify soils that supported maximum mangrove establishment and growth under the harsh arid coastal conditions of Kuwait. For this purpose, eight soil profiles (four each representing areas where seedlings established successfully and grew vigorously and where all seedlings died in the initial stages of establishment) were investigated...
TL;DR: The results clearly indicate that wet seeding spot method of rice planting is an improved method that gives higher yield with less requirement of water and labour and easy weed management than the existing methods.
Abstract: This experiment was done to assess the effect of different direct seeding methods and transplanting of rice (Oryza sativa L.), cv. Naveen on growth, grain yield and its yield components. The water-use efficiency of the production systems, comparative weed growth as well as labour requirements under each method was also studied. The different direct seeding methods of planting like dry seeding by broadcast (DSB), wet seeding by broadcast (WSB), wet seeding by broadcast followed by beushening (WSBB), wet seeding in line (WSL) and wet seeding in spots (WSS) were compared with the traditional transplanting (TPR) method. WSS gave significantly higher yield (11.8%) compared to TPR due to higher tillering, more panicle, and better grain filling. Weed population under DSB, WSB, and WSS were 5, 4, and 2 times more than that under TPR, respectively. Total water requirement for growing rice crop under transplanting, wet seeding and dry seeding methods of planting were 1041.2, 941.5 and 915.0 ha-mm, respectively. Wat...
TL;DR: In this article, the authors investigated the total content of six heavy metals, Cd/Zn ratio and the Zn-equiv, the relative availability and fractionation study to assess the suitability of compost derived out of those for environmental concerns.
Abstract: How composting affects heavy metal content is largely unknown. Accordingly, we investigate the total content of six heavy metals, Cd/Zn ratio and the Zn-equiv, the relative availability and fractionation study to assess the suitability of compost derived out of those for environmental concerns. During composting, total metal content increased but their RA decreased. As a result of composting bioavailable form of metals also decreased. High significant correlations between different forms of heavy metals content and degree of humification were found for all the elements. Composting increases humic acid content than fulvic acid. This transformation is mainly responsible to serve as binding agent for metal thereby moderating the rapid metal mobilization.
TL;DR: In this paper, total soil organic matter and its decomposable part have been studied in arable farm fields in the Czech Republic, where one hundred and forty localities have been selected.
Abstract: Total soil organic matter and its decomposable part have been studied in arable farm fields in the Czech Republic. One hundred and forty localities have been selected. Besides the soil types and subtypes (taxonomical soil units), textural units, total organic carbon content, and even geographical distribution was taken into account. Soil samples have been taken from the top soil (0 – 20 cm) at the selected sites and a number of analyses were carried out. Organic C content in the top soil from the selected 140 sites on arable soils ranged between 1% and 2% in more than 80% of the soil samples. C/N ratio oscillated around 10 in a rather narrow band. There were no remarkable changes in the organic C content in the top soil in 82 sites over the last decade (1992 to 2002). The distribution of the organic C content in the soil samples according to the taxonomical soil units have shown the lowest values in the Haplic Luvisols and Albeluvisols. Their variability was relatively low. In Cambisols, on the contrary, ...
TL;DR: Spatial structure of the soil landscape and some process-relevant topsoil parameters were analysed on two Holocene lowland sites and the peatland site indicates distinct anthropogenic changes of theTopsoil.
Abstract: Spatial structure of the soil landscape and some process-relevant topsoil parameters were analysed on two Holocene lowland sites: The river lowland site Seelow located in the upper Oderbruch region, and the fen peatland site Ziethenhorst, located in the upper Rhinluch region. Along typical transects the thickness of the holocene clay and the peat layers was detected by sampling distances of 5 – 20 meters. Parameters of the soil substrate and structure in particular the water retention were analysed. Spatial structure of the sites (clay and peat thickness) and current soil properties were largely determined by the site conditions during the late Pleistocene and early Holocen periods. Relief and hydrological conditions of former rivers and adjacent sedimentation or peat forming areas have main influence on spatial substrate variability and on topsoil properties in combination with groundwater table. Basic structure of tiny alluvions (former small rivers) are not recognizable by sampling distances > 10 m, bu...
TL;DR: The bulk of the contaminant As at the sites seemed to be associated with soil amorphous Fe and Al minerals and the dominant clay minerals which help in As sorption are montmorillonite and mica, which might provide a good index of potential As bioavailability and mobility.
Abstract: A sequential fractionation scheme, based on a soil phosphorous fractionation, was developed to assess the chemical nature, and thus the potential bioavailability and mobility of As, at the sites. Soil As was separated into five fractions with (i) anion exchange resin, (ii) NaHCO3, (iii) NaOH, (iv) HCl, (v) residual. Most sites contained relatively low concentrations of As in the two most labile fractions. The bulk of the contaminant As at the sites seemed to be associated with soil amorphous Fe and Al minerals and the dominant clay minerals which help in As sorption are montmorillonite and mica. Resin-extractable As in particular might provide a good index of potential As bioavailability and mobility.
TL;DR: The spatial distribution map helped to determine zones with different As concentrations, making it possible to identify high-risk zones, and the local population living around these areas is vulnerable and exposed to arsenic contamination.
Abstract: Arsenic pollution in ground water in India and Bangladesh is considered to be the largest contamination problem in the world. About 15 – 18% of the area of West Bengal, India comes under the threat of arsenic (As) contamination and around 5.36 million people are exposed to this hazard. A detailed isoline map corresponding to variations in arsenic concentration and their spatial distribution was prepared for the study area, which comprised two villages Ghentugachi and Gotera in Nadia district, West Bengal and the total area covered was 808 hectares. The pattern of arsenic contamination was highly irregular and diverse. About 11.2% of the study area was affected most ( > 0.50 mg As l−1) with sample As values reaching 0.71 and 0.80 mg l−1. About 22.5% of the area had As content between 0.20 and 0.50 mg l−1 and 33.9% of study area had As content below the WHO guideline of 0.01 mg As/l. Thus the local population living around these areas is vulnerable and exposed to arsenic contamination. None of the water sam...
TL;DR: It is suggested that rose-scented geranium can be harvested more frequently on attainment of shoots with 4 fully expanded leaves in order to produce higher essential oil yield with superior quality and higher return.
Abstract: Rose-scented geranium (Pelargonium species) is grown as a perennial crop for production of high value essential oil, which finds application particularly in high-grade perfumery, cosmetic products and aromatherapy. A field investigation was carried out during 2001-02 to study the harvest of shoots of the crop on attainment of 4, 6 or 8 fully expanded leaves (FEL) and its effect on essential oil yield and quality under semi-arid tropics. Harvesting of shoots with 4 FEL produced 6 harvests / annum against 4 and 3 harvests per annum in the treatments representing harvest of shoots with 6 and 8 FEL, respectively. Highest biomass yield (18.1 t ha−1 annum−1) among the treatments was, however, observed in the treatment 8 FEL. On the contrary, essential oil content in the biomass of treatment of 4 FEL was 27.3 and 55.5% higher than 6 FEL and 8 FEL treatments, respectively. Similarly, estimated essential oil yield in the treatment of 4 FEL was 17.4 and 30.7% higher than 6 FEL and 8 FEL treatments, respectively. Fu...
TL;DR: In this paper, the authors suggested an incubation test of thirty days in duration with soil samples amended or not with lucerne meal as a source of plant carbon, and the results obtained with samples from non-fertilized or long-term ( > 40 years) fertilized plots of two field trials indicate that fertilization by NPK+ farm yard manure resulted in a slight enhancement of C mineralisation, i.e., CO2 release from soil, and significant increases of humic acids and fulvic acids (FA) contents.
Abstract: Since life is inevitably dependent on the assimilation and dissimilation of carbon, and since most of the organic carbon is bound in soil humic matter, the mineralisation and humification of plant carbon in soil should be monitored, so as to evaluate soil quality and avoid ecological risks. For this reason we suggested an incubation test of thirty days in duration with soil samples amended or not with lucerne meal as a source of plant carbon. During the incubation period, CO2 release is to be measured repeatedly, and thereafter contents of humic acids (HA) and fulvic acids (FA) should be estimated and compared with those determined in the original soil samples. Our results obtained with samples from non-fertilized or long-term ( > 40 years) fertilized plots of two field trials indicate that fertilization by NPK + farm yard manure resulted in (i) a slight enhancement of C mineralisation, i.e., CO2 release from soil, and (ii) a significant increases of HA and FA contents. Soil samples from a reclaimed mine ...
TL;DR: Investigation of the effect of wheat, legume and legume enriched wheat residue (WR) on soil fertility under the rice-wheat cropping system found incorporation of WR with SGM and MBR with adequate fertilizer-N is recommended for building up organic C, kjeldahl-N and available K content in soil.
Abstract: The field experiments were conducted for two crop years of 1997 – 98 and 1998 – 99 at the Indian Agricultural Research Institute, New Delhi to study the effect of wheat, legume and legume enriched wheat residue (WR) on soil fertility under the rice-wheat cropping system. A rice-wheat cropping system without incorporation of residue depleted organic C over initial level by 0.061%, kjeldahl-N by 0.012%, available P by 0.7 kg ha − 1 and available K by 36 kg ha − 1, whereas incorporation of Sesbania green manure (SGM), mungbean residue (MBR), SGM + WR and MBR + WR increased organic C over the initial level by 0.071, 0.100, 0.163 and 0.133%, respectively, kjeldahl-N by 0.001, 0.004, 0.001 and 0.005% respectively, available P by 2.7, 5.0, 8.5 and 3.2 kg ha − 1, respectively and available K by 35, 5, 92 and 12 kg ha − 1, respectively in 2 years. As compared with no residue control, incorporation of WR increased organic C by 0.036 – 0.102%, kjeldahl-N by 0.002 – 0.007% and available K by 23 – 45 kg ha−1, whereas ...
TL;DR: In this article, the results of long-term measurements of wind erosion in Brandenburg were presented, and the results were used to validate the Wind Erosion Prediction System in Germany.
Abstract: This paper presents results of long-term measurements of wind erosion in Brandenburg. Although considerable amounts of material can be transported, the perception of wind erosion in the field site is difficult. Already investigations of Chepil (1960) showed the possibility of annual soil losses up to 40 t/ha without any visible signs of the erosion process. Therefore a main task were the quantification to get reliable data of soil losses by wind erosion in Brandenburg. Meanwhile, data of 10 years of measurements were collected. Some of the most interesting results will be presented in this paper. Data are also used to validate the Wind Erosion Prediction System in Germany.
TL;DR: In this paper, a 14C pulse labelling and sterilization of soil, a C release into soil of 14, 18, and 23% of net CO2 assimilation was observed during vegetation period (excluding root respiration).
Abstract: By means of 14C pulse labelling and sterilization of soil, a C release into soil of 14 – 18% of net CO2 assimilation (corresponding to 23 – 26% of 14C incorporated in plant tissue) was observed during vegetation period (excluding root respiration). Microbial colonization increased this rhizodeposition. About 60 – 80% of the primary root-borne compounds were very quickly respirated by microorganisms (secondary respiration of exudates). Fourteen to 38% (corresponding to 130 – 400 kg C ha−1 a−1) of the remaining rhizodeposites were located in a zone close to root surface (up to 5 mm). Their solubility in water decreased with increasing distance to the root. The fraction of water-soluble root exudates included primarily carbohydrates (sucrose, glucose, fructose, ribose), amino acids/amides (glutamine, serine, aspartic acid) as well as organic acids (citric, succinic and tartaric acids). The water-insoluble portion of rhizodeposites were strongly absorbed by soil clay-fraction and substantially increased stabi...
TL;DR: The results clearly proved the advantage of organic matter recycling combined with mineral fertilization over treatment 1 and resulted in significantly higher Corg contents compared to mineral N fertilization without farmyard manuring or incorporation of crop residues.
Abstract: The effect of various combinations of organic and mineral N fertilizers was studied on the organic matter content of the soil, grain yield, dry matter production and N-uptake of maize. In a model experiment, large pots were filled with 55 kg sandy loam soil originating from the plots of the ‘International Long-term Experiments for Investigating the Effect of Organic and Inorganic Fertilisers’ (IOSDV), Keszthely. The field experiment, which was set up in 1983, contained three crop-rotations with maize, winter wheat and winter barley. Treatments: (1) inorganic fertilizers only with increasing N-doses (N); (2) farmyard manuring (FYM) in every third year+N; (3) stalk, straw or green manure+N. Our results clearly proved the advantage of organic matter recycling combined with mineral fertilization over treatment 1. In the fifth and sixth rotations, both types of organic matter recycling resulted in significantly higher Corg contents compared to mineral N fertilization without farmyard manuring or incorporation ...