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The best-known and most remarkable example of continuous production in Hungary is the Westsik crop rotation experiment established in 1929. It is still in use to study the effects of organic manure treatment, to develop models and to predict the likely effects of different cropping systems on soil properties and crop yields. In this respect, the Westsik crop rotation experiment provides data of immediate value to farmers concerning the application of green manure, straw and farmyard manure. The increased demand for food and changes in the ecological requirements of agricultural production have urged scientists to revise the widely used traditional principles and to develop alternative crop production practices. In this respect, they must strive for the adoption of technologies which serve for the simultaneous maintenance of production levels, soil fertility and environmental goals. The Westsik crop rotation experiment provides useful help and a thorough scientific basis for the solution of this problem. It models various possible methods of nutrient management and assists in answering questions on the sustainability of agricultural production. Since 1929, only minor changes have been introduced in some treatments. These changes have made the classical experiment more relevant to current research needs and farming practices.

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A field experiment was carried out to investigate the establishment of phosphate-dissolving strains of Azotobacter chroococcum, including soil isolates (wild type) and their mutants, in the rhizosphere and their effect on the growth attributes and root biomass of three genetically divergent wheat cultivars (Triticum aestivum L.). Four fertilizer doses were applied: 90 kg N ha—1, 90 kg N + 60 kg P2O5ha—1, 120 kg N ha—1and 120 kg N + 60 kg P2O5ha—1, besides a control plot without fertilizers or bioinoculants. Phosphate-solubilizing and phytohormone-producing parent soil isolates and mutant strains of A. chroococcum were isolated and selected following the enrichment method. On an overall basis the mutant strains performed better than the soil isolates for in vitro phosphate solubilization (11–14%) and growth hormone production (11.35%). Seed inoculation of wheat varieties with phosphate-solubilizing and phytohormone-producing A. chroococcum showed a better response over the control. Mutant strains of A. chroococcum showed a higher increase in grain (15.30%) and straw (15.10%) yield over the control and better survival (12–14%) in the rhizosphere as compared to their parent soil isolate (P4). Mutant strain M15 performed better in all three varieties in terms of increase in grain yield (20.8%) and root biomass (20.6%) over the control.

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The results obtained showed that there was severe competition between potato and the predominant weed species Coronopus didymus, Chenopodium album, Fumaria parviflora, Melilotus indica and Spergula arvensis. Competition by other weed species was nominal. The maximum reduction in tuber yield due to weed competition was 50.5% in 1997–98 and 63.4% in 1998–99. Weed control treatments lowered the weed density and weed biomass and scaled up tuber yield in both the years, but their effect on weed species differed. Metribuzin killed all the Chenopodium album plants and gave excellent control of Coronopus didymus (94%) and effective control of other weed species. Pendimethalin inhibited the germination of Chenopodium album, gave good control of arvensis and lowered the density of other weed species. Fluchloralin completely inhibited the germination of Fumaria parviflora and gave good control of Chenopodium album and Spergula arvensis, but was least effective against other weed species. The highest yield was recorded in the weed-free treatment, which was significantly superior to all other treatments. Hand weeding + earthing up, isoproturon (1.0 kg/ha), metribuzin and pendimethalin caused an identical increase in tuber yield, which was significantly higher than the increase in the rest of the treatments. Atrazine at 0.25 kg ha –1 resulted in a higher increase than when applied at 0.5 kg ha –1 . Fluchloralin, paraquat and paddy straw mulch boosted up production, but the increase in tuber yield was not significant.

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Effects of one pre-emergence herbicide (terbutryn/terbuthylazine) and one post-emergence herbicide (bentazone) along with unweeded and hand-weeded controls on weeds and on the nodulation, nitrogenase activity, nitrogen content, growth and yield of pea (Pisum sativum) were studied. Terbutryn/terbuthylazine was applied pre-emergence @ 1.40, 2.80 and 5.60 kg/hawhereas bentazone was sprayed 6 weeks after sowing @ 1.44, 2.88 and 5.76 kg/h. Terbutryn/terbuthylazine controlled all the weeds very effectively, whereas bentazone did not control some weeds such as Polygonum aviculare, Poa annua and Elymus repens. The herbicides decreased the number of nodules, the dry weight of nodules, the nitrogenase activity, the shoot dry weight, the nitrogen content in the straw and seeds, and the seed yield of peas, the effects generally being higher at higher rates of application. The adverse effects of herbicides on these parameters might be due to their effects on plant growth, as both the herbicides are known to adversely affect photosynthesis. Nitrogenase activity did not correlate well with plant-N content or shoot dry weight. However, there was a strong relationship between plant biomass and plant-N content, which suggests that researchers can rely on these parameters for studying the effects of treatments on nitrogen fixation, rather than measuring nitrogenase activity.

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A new wheat variety resistant to cereal cyst nematode (CCN), CCNRV 1 (Raj Molya Rodhak 1), was developed from two genetically diverse cultivars in a single cross (J 24/AUS 15854). This variety exhibited a higher level of productivity in both CCN-infested and normal soils, with increases in the grain and straw yields of 78.7% and 60.1%, respectively, over Raj 3077 in infested soils. It also gave 19.0% higher yield than local varieties under timely-sown irrigated conditions in normal soils. It possesses superior grain quality along with other desirable agronomic traits. Genetically it carries a dominant gene for CCN resistance. It is a robust and reliable wheat variety that offers a high degree of resistance against nematodes in warmer areas of Rajasthan. It was recommended for timely-sown, irrigated conditions in CCN-infested areas of Rajasthan by the State Seed Sub-Committee on Crop Standards, Notification and Release of Varieties in September 2002. It is envisaged that this variety will help to boost wheat production and alleviate the socio-economic problems of subsistent Indian farmers in CCN-infested areas.

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The influence of organic and nitrogen fertilization on the amount and quality of wheat yield was examined in Keszthely on Ramann's brown forest soil containing an average level of potassium, a low level of phosphorus and a medium level of nitrogen. The experiment involved treatments with 0-200 kg/hectare of nitrogen, 100 kg/hectare each of phosphorus (P2O5) and potassium (K2O), farmyard manure, straw and green manure, together with a non-fertilized control. Nitrogen fertilization had a substantial effect on the yield (the 1.98 t/hectare yield was increased threefold by 200 kg/hectare of nitrogen). The treatments modified the quality of wheat significantly. Nitrogen fertilization together with farmyard manure increased the gluten content (to 35.8% compared to 11.35% in the control). The farinographic index increased to 77.4 (from 33.9 in the control) and the Zeleny number also increased significantly (from 10 in the control to 35.5). When low rates of nitrogen were applied overall improvement was not achieved in spite of the favourable influence of farmyard manure.

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A field experiment was conducted to investigate the effect of soil application of zinc fertilizer on yield and yield components of wheat ( Triticum aestivum L. cv. Inqlab 91) grown on calcareous soil in Pakistan. The levels of zinc sulphate were 0 (control), 5, 10, 15, 20, 25 and 30 kg ha −2 and the zinc sulphate was combine-drilled at the time of sowing. Zinc sulphate increased the Leaf Area Index, the total number of fertile tillers m −2 , number of spikelets spike −2 , spike length, grain spike −2 , thousand grain weight, grain yield, straw yield and biological yield and decreased harvest index. Most of the response trends were curvilinear although the decrease in harvest index was linear. All applications of zinc sulphate gave economic increases in margins over costs but the application of 5 kg ha −2 gave the highest marginal rate of return. It is recommended that under such calcareous soil conditions growers can expect good returns from the application of 5 kg zinc sulphate ha −2 at the time of sowing but if the grain price were to increase or the price of zinc sulphate were reduced economic responses could be expected from higher levels of zinc sulphate.

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The results obtained showed that there was severe competition between wheat and the predominant weed species Phalaris minor, Avena ludoviciana and Melilotus indica. Competition by other weed species was normal. The maximum reduction in grain and straw yields due to weed competition was 34.8% and 43.7%, respectively. Weed control treatments lowered the weed population and weed biomass accumulation and boosted up the crop yield. A significant reduction in the weed population and weed dry weight was observed with increasing doses of both atrazine and metribuzin. Metribuzin at 200 g ha-1 killed all the plants of M. indica and gave excellent control of both P. minor (98%) and A. ludoviciana (89%). Atrazine at higher doses had an almost similar effect on P. minor, A. ludoviciana and M. indica with 83-87% control. Pendimethalin gave good control of P. minor and M. indica (75-83%) but poor control of A. ludoviciana (55%). The highest yield was recorded in hand weeding which was significantly superior to all other treatments. Metribuzin at 100 g ha-1 was the next best treatment, and this rate was superior to the higher doses. Pendimethalin and atrazine also brought about a marked increase in the crop yield. Higher doses of atrazine and metribuzin had a phytotoxic effect on the crop, reducing the number of productive tillers and finally lowering the crop yield, despite their excellent control of dominant weed species.

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Because of the need for renewable energy resources, cellulose, which can be enzymatically hydrolyzed to glucose, has drawn lot of attention during the past decade. However, the process of cellulose conversion using cellulase is not yet economically feasible because of the high cost of enzymes. Factors influencing the cellulase production of Trichoderma koningii using both acid and steam treated sugar cane bagasse and rice straw as carbon sources were investigated. The highest levels of cellulase activities were obtained using a culture medium containing urea and (NH4)2SO4 together as nitrogen sources at 0.217% and 0.241% for both carbon sources. When the culture medium was supplemented either with 0.5% Tween 60 or Tween 80, the rate of cellulase production was increased considerably. Maximum levels of both filter paper and CMC-ase activities produced on both media were obtained at 25 °C and 100 r.p.m., while the highest level of â -glucosidase production was obtained at 30 °C and 200 r.p.m.

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The current study was carried out in both pot and field conditions to investigate the effects of three KSB strains of Pantoea agglomerans, Rahnella aquatilis and Pseudomonas orientalis on nitrogen (N), phosphorous (P) and potassium (K) uptake, nutrient use efficiency parameters and nutrients remobilization in rice (Oryza sativa L. cv. Pajohesh). The experiments included 15 treatments of KSB inoculations, commercial K biofertilizer and K chemical fertilizer. The results showed that the inoculums of all three KSB strains increased the K, N and P uptake by grain and straw, especially when applied in combination with ½ K chemical fertilizer (47.5 Kg/ha) as compared to the control treatment. The highest value of available K in the soil obtained from NPK chemical fertilizer equal to 140.1 and 134.6 mg K per kg of soil in the pot and field experiments, respectively, which were significantly higher than KSB inoculations treatments. Bacterial inoculums coupled with ½ K chemical fertilizer also enhanced the nutrient use efficiency (including agronomic efficiency (AE), apparent recovery efficiency (ARE), physiological efficiency (PE), agro-physiological efficiency (APE), internal utilization efficiency (UE), partial factor productivity (PFP), partial nutrient balance (PNB)) and nutrient remobilization. The results indicated that the bioinoculation with these KSB strains isolated from soil paddy could be considered as an effective way to increase potassium, nitrogen and phosphorus uptake by rice plant and enhance their use efficiency and remobilization to grains in the flooding irrigation conditions.

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