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1.
Field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai, India, during the wet seasons of 1992 and 1993 to study the effect of full and partial substitution of fertiliser N with green manure N (Sesbania rostrata) on nitrogen uptake, yield attributes and yield of rice. The experiment consisted of eight treatments with two levels of N (100 and 200 kg ha−1) and three sources of N application viz., fertilizer, integrated (1:1 fertilizer and green manure N) and green manure N compared to the recommended practice (150 kg fertilizer plus 6.25 t ha−1 (72 kg N) green manure) and a no N control. Nitrogen application markedly increased the N uptake. Combined use of the two N sources at 200 and 222 kg N ha−1 and of single fertilizer N at 200 kg N ha−1 recorded the maximum N uptake, increased the yield attributes such as number of panicles per unit area, weight per panicle, number of total and filled grains per panicle and test weight. At 200 kg N ha−1 full substitution of N by green manure reduced the grain yield but only partial substitution of N by green manure resulted in almost similar yield as single fertilizer N. Thus 200 kg N ha−1 applied in equal proportions of fertilizer and green manure N can be recommended for medium duration rice cultivars.  相似文献   

2.
An experiment was conducted over the period 1995–96 in a warm-temperate environment in Nepal to investigate the effect of cutting frequency on forage yields of three temperate legume species, grown during the winter season, and the residual treatment effects on a subsequent upland rice crop. The three species, Persian clover ( Trifolium resupinatum ), white clover ( Trifolium repens ) and vetch ( Vicia benghalensis ), proved to be well adapted to the winter growing conditions and produced cumulative forage yields between 6.8 t DM ha−1 (vetch) and 9.2 t DM ha−1 (Persian clover). Vetch grew vigorously throughout the winter months and provided reasonable forage yields between December and February, whereas the clovers provided green fodder up to July. These species may therefore make a substantial contribution to alleviating the severe shortage of quality feed during the winter months. Grain yields of the subsequent rice crop ranged from 3.6 to 7.3 t ha−1. Rice yields were greatly affected by the previous legume species and forage management practices. In general, the removal of legume forage greatly reduced the residual effect, and farmers will have to seek a compromise between maximizing green fodder production and the immediate beneficial residual effect of the legume crop on rice yield.  相似文献   

3.
A 1-year study was conducted in 1983/84 at 2 experimental sites in Brazil to determine the effect of Azolla green-manure (AO), A. intercrop (OA) and their combination (AA) on rice yield in comparison to mineral fertilization with urea. Nitrogen sources were combined with 4 rice sowing/planting systems.
On terraced terra-roxa soil (Paleudalf) in subtropical northern Paraná State, transplanted rice (T) yielded 8.66 t · ha−1 compared to pregerminated (P), direct-sown (D) and conventionally sown (C) rice with 7.92; 7.73 and 7.48 t · ha−1, respectively. N-source treatments yielded 9.33; 8.54 and 7.34 t · ha−1 for AA, OA and AO compared to 8.46; 7.98 and 6.05 for 100, 50 and 0 kg N · ha−1, respectively. Fertilizer-nitrogen equivalence (FNE) of Azolla treatments compared to urea broadcast in 3 applications ranged between 0 and more than 100 kg N · ha−1.
On hydromorphic latosol (Ustic Dystropept) in tropical Goiás State, rice yields were 4.07; 2.52; 1.46 and. 1.33 t · ha−1 for systems T, P, C and D, respectively. N-source treatments yielded 2.79; 1.98 and 1.78 t · ha−1 for AA, AO and OA compared to 3.43; 2.63 and 1.46 t · ha−1 for 60; 30 and 0 kg N · ha−1 as urea broadcast in 2 applications, respectively. FNE of Azolla was between 0 and 56 kg N · ha−1.  相似文献   

4.
Results reported in the literature with regard to productivity of intercropping systems in comparison to sole cropping are very inconsistent. A field experiment was therefore conducted in the northern part of the Guinea Savanna in Ghana to compare the productivity of maize/cowpea mixed cropping, maize/cowpea relay intercropping with maize/cowpea rotation and maize monocropping over a 4-year period. The treatments included two levels of nitrogen (0 and 80 kg of N ha−1 y −1 as urea) and two levels of phosphorus application (0 and 60 kg of P ha−1 y−1 as Volta phosphate rock). At all levels of N and P application, maize yields of the intercropping systems, especially of maize/cowpea mixed cropping, were significantly lower than in sole cropping. Highest maize yields were obtained in maize/cowpea rotation, which in contrast to the other cropping systems did not show any reductions in yields over years. Cowpea yields were generally less affected by the cropping system, but were notably depressed when cowpea was relay-intercropped with maize. In treatments without fertilizer application (N and P) Land Equivalent Ratios (LER) and Area x Time Equivalency Ratios (ATER) generally indicated lower productivity of the intercropping systems as compared to sole cropping, with the maize/cowpea rotation showing the highest productivity. Conversely, fertilizer application resulted in higher productivity of the intercropping systems over the 4-year period. Productivity on the basis of ATER was generally lowest in maize/cowpea relay-intercropping as a consequence of the long time of land occupation. All of the parameters indicate low productivity of maize monocropping, clearly demonstrating that crop sequence as well as fertilizer application must be considered as important for maintaining high production levels at this site.  相似文献   

5.
This study was conducted at the University of Jordan Research Station in the central Jordan Valley during 1988 and 1989 summer growing seasons, to determine the potential and response of summer crops to intercropping system and to poultry manure addition. Corn, soybean and watermelon were grown as sole crops and as intercrops in three paired combinations (corn: watermelon, corn: soybean, watermelon: soybean) with three levels of poultry manure (0, 20, 40 t/ha). The crop yields and land equivalent ratios (LERs) were determined for all treatments. The highest yields for the two cropping systems were obtained in response to the highest poultry manure addition. Corn gave the highest yield when intercropped with soybean, where increases in yield of 45 % and 66 % were obtained over those of corn sole crop at the same level of poultry manure (40 t/ha), in 1988 and 1989 seasons, respectively. Soybean gave the highest yield when grown with corn leading to an increase of 35 % and 34 % over soybean sole crop grown at the same level of poultry manure (40 t/ha) in 1988 and 1989, respectively. Watermelon gave the highest yield when grown with soybean, giving an increase which ranged from 390 to 920 kg ha−1 over the yield of sole cropping system under the same level of poultry manure (40 t/ha). The LER values for all intercrop treatments were greater than 1.0 which gave clearly an indication for the superiority of the intercropping over the sole cropping system especially when 40 t ha−1 poultry manure was added.  相似文献   

6.
Tomato ( Lycopersicon esculentum mill. cv. Petopride ) is the most important vegetable crop in Jordan; its production is characterized by inadequate irrigation and fertilization practices, especially under open field conditions. A field study was carried out to determine the effect of different irrigation intervals and different N-fertilizer doses on water use, tomato yields and residual soil nitrogen.
Results indicated significant differences in water use and tomato yields between irrigation treatments. Highest yield (51.4 ton ha−1) was obtained under three irrigations per week with 504 mm total water supply, whereas under irrigation once a week 35.3 ton ha−1were produced with 353 mm total water supply. There were no significant differences in yield between fertigation with ten equal time intervals and fertigations with intervals as per crop requirements, the yields were 47.1 ton ha−1 and 44.5 ton ha−1, respectively. However, yield was significantly lower with three fertigations at equal intervals and equal doses (35.8 ton ha−1) throughout the season. There were no significant differences between mineral nitrogen forms in terms of yield effects. Significant irrigation effects were observed on total soil nitrogen. Residual soil N was 0.052% in the surface layer (0–30 cm), and 0.030% in the subsurface layer (30–60 cm).  相似文献   

7.
A field experiment was conducted during 1994 and 1995 at Lucknow (26.5°N, 80.5°E, 120 m above mean sea level) to optimize planting density and fertilizer-N application for high essential oil yield of late transplanted mint ( Mentha arvensis ). The treatments studied were 2.5, 2.0 and 1.66 × 105 mint seedlings ha−1 and 0, 80, 160 and 240 kg N ha−1. Under 3 months delayed planting conditions using 2-month-old seedlings, the high planting density of 2.5 × 105 plants ha−1combined with 160 kg N ha−1 gave significantly higher herb and essential oil yields compared with those of lower planting densities (2 and 1.66 × 105 plants ha−1) and all other rates of N application. It is demonstrated that a transplanted mini crop, yielding essential oil at a level of 164 kg ha−1, is feasible after the harvest of rabi cereal, oil seed or legume crops in the north Indian plains.  相似文献   

8.
Determination of optimal N-fertilization rates, NOR , for crop production that minimize risk of environmental degradation require accurate application of a response model. Several models are available to describe crop yield response to N fertilization. The objective of this work was to compare the relative accuracy of a quadratic, f(N Q), a modified Mitscherlich, and tanh( N ) models on 48 data sets. Data were collected from a Tara silt loam (fine-silty, mixed, frigid Pachic Udic Haploboroll) over a 6-year period using two maize ( Zea mays L.) hybrids and four tillage treatments, mouldboard plough, chisel plough, ridge tillage and no-tillage. In about one-third of the cases, all models performed about equally well. Generally, the tanh( N ) and modified Mitscherlich models gave better fit between N rate and grain yield data. The NOR, ranged from about 140 to 170 kg ha−1 for the modified Mitscherlich model, 136 to 184 kg ha−1 for the tanh( N) function, and 124 to 173 kg ha−1 using the f(N Q) model. Estimated grain yields at these rates ranged between 6.58 ± 1.30 to 7.59 ± 1.69 Mg ha−1 for the 90-day Minnesota maturity rated (MR) hybrid and between 7.52 ± 2.40 to 8.72 ± 1.70 Mg ha−1 for the 95-day MR hybrid.  相似文献   

9.
To compare the feasibilities of pearlmillet-based intercropping systems, field experiments were carried out for 2 years on loamy sand soils in the semi-arid plain zone of Rajasthan, India. Results showed that the pooled yields of pearlmillet from the single crop (1525 kg ha−1) and from the crop intercropped with legumes (1528, 1498 or 1540 kg ha−1) were statistically the same. The yields from intercrop legumes were obtained as a bonus. The highest value of land equivalent ratio (1.21) was recorded for the pearlmillet + clusterbean system, which gave significantly better results than the pearlmillet + cowpea system. It was also found that the dose of nitrogen can be reduced by up to 25 % when pearlmillet is grown with legumes. However, intercrop legumes required the recommended dose of fertilizer to produce their optimal yields. The practice of intercropping without fertilizer proved disadvantageous.  相似文献   

10.
In a 3-year experiment on a Typic Haplustert low in soil test sulphur (S), the response to applied farmyard manure (FYM) and S was studied in terms of the nodule production, nodule dry weight, chlorophyll content, dry matter production and seed yield of soybean. FYM was applied to soybean at four levels (0–16 t ha−1). S as gypsum was also applied at four levels (0–60 kg ha−1) to both soybean and wheat every year. Both total and active nodule production, nodule dry weight, dry matter production and seed yield of soybean were increased significantly by the application of both FYM and S. However, the proportion of total nodules to active nodules fell sharply for applications higher than 8 t FYM and 40 kg S ha−1.  相似文献   

11.
Field experiments were conducted to determine the effects of tillage (ploughing followed by one rotary hoeing (CT), rotary hoeing (MT) and no-tillage (NT)) and type of fertilization (NP 154/75 kg ha−1, digested farmyard manure 30 t ha−1) on growth (biomass and roots), N-accumulation and nodulation of vetch plants (Vicia sativa cv. Alexander) at different stages. The highest dry matter yields and root weight were determined for the NT and the lowest for the CT systems. The NT system promoted nodulation of vetch plants to a higher degree than the MT and CT systems. At the time just before harvesting, the N-accumulation in the above ground plants, was 54.3 for CT, 76.7 for MT, and 109.0 kg ha−1 for NT, and the corresponding values at roots were 73.3, 112.0 and 173.3 kg ha−1. Growth and nodulation of vetch plants was in general much better on farmyard manure plots than it was with the NP fertilization. The closest correlation coefficients between dry matter of biomass and roots on the one hand, and number of nodules and percentage N in roots on the other, were found with NT. The highest correlation between nodulation and percentage N in roots (r = 0.91***) was observed at the 128-days-old vetch plants. The highest correlation between the number of nodules and percentage N in biomass (r = 0.82**) was found at the beginning of the plants' flowering period. *, **, *** indicate significance at P = 0.05, 0.01 and 0.001 respectively.  相似文献   

12.
In a 3-year field experiment conducted on a Gleyic Luvisol in Stuttgart-Hohenheim, ten maize cultivars (nine commercial and one experimental hybrid) were compared in their ability to utilize a high soil nitrogen (N) supply. Total N content of the shoots at about silage maturity ranged from 213 to 328 kg N ha−1 (1986), from 177 to 223 kg N ha−1 (1987) and from 185 to 226 kg N ha−1 (1988). In all three experimental years, total shoot N uptake was significantly positively correlated to stover yield, and also to N concentrations in the ears and in the total plant dry matter. In contrast, a negative correlation between ear yields of the cultivars and total N uptake was indicated. Differences between the cultivars in N uptake were reflected in a corresponding soil nitrate depletion. At harvest, residual nitrate-N in the 0–90 cm soil layer ranged from 34–63 kg N ha−1 m 1987 and 32–71 kg N ha−1 in 1988. The results indicate, that growing of cultivars selected for high N uptake-capactiy of the shoots may contribute to an increased utilization of a high soil N supply and thus to a reduction of nitrate leaching.  相似文献   

13.
Field experiments were conducted to determine the direct and residual contributions of legumes to the yield and nitrogen (N) uptake of maize during the wet seasons of 1994 and 1995 at the University Farm, Abubakar Tafawa Balewa University, Bauchi, Nigeria, located in the Northern Guinea savannah of Nigeria. Nodulating soybean, lablab, green gram and black gram contributed to the yield and N uptake of maize either intercropped with the legumes or grown after legumes as a sole crop. Direct transfer of N from the nodulating soybean, lablab, green gram and black gram to the intercropped maize was 24.9–28.1, 23.8–29.2, 19.7–22.1 and 18.4–18.6 kg N ha–1, respectively. However, the transfer of residual N from these legumes to the succeeding maize crop was 18.4–20.0, 19.5–29.9, 12.0–13.7 and 9.3–10.3 kg N ha–1, respectively. Four years of continuous lablab cropping resulted in yields and N uptake of the succeeding maize crop grown without fertilizer N that were comparable to the yields and N uptake of the succeeding maize crop supplied with 40–45 kg N ha–1 and grown after 4 years of continuous sorghum cropping. It may therefore be concluded that nodulating soybean, lablab, green gram and black gram may be either intercropped or grown in rotation with cereals in order to economize the use of fertilizer N for maize production in the Nigerian savannah.  相似文献   

14.
A field experiment was conducted at the Division of Agronomy, Indian Agricultural Research Institute, New Delhi during 1983-84 and 1984-85 to study the effect of lentil residues on the yield and response of succeeding rice to nitrogen. Lentil residues benefitted the succeeding rice and gave longer and heavier panicles, more grains per panicle, higher 1000-grain weight and higher grain and straw yield of rice as compared to fallow. Rice responded well to applied nitrogen both in the absence and presence of lentil residues. The effect of lentil root residues and root residues plus incorporation of lentil straw was equivalent to 11 and 33 kg N ha−1 when 60 kg N ha−1 was applied to rice; the corresponding values being 54 and 60 kg N ha−1 when 120 kg N ha−1 was applied to rice.  相似文献   

15.
A field experiment was conducted during the winter seasons of 1992–93 and 1993–94 at Anand to study the effect of FYM, nitrogen and source of fertilizer on growth and yield of mustard [ Brassica juncea (L.) Czernj & Cosson]. The results showed significant variation in leaf area index (LAI), crop growth rate (CGR), dry matter production and seed yield. The direct effect of farmyard manure (FYM) was conspicuous in improving the growth of mustard. FYM application at 10 tonnes ha−1 significantly increased the LAI, CGR and dry matter accumulation per plant at almost all the stages during first year study (1992–93) and in pooled analysis. Similarly, nitrogen application registered maximum LAI, CGR at 75 kg level and RGR and NAR at 50 kg level at almost all the during both years. Sulphur carrying source (Ammonium sulphate plus single super phosphate) increased all stages growth characters. Maximum dry matter accumulation per plant and seed yield were recorded with highest levels of FYM (20 tonnes ha−1), N (75 kg ha−1) and source having S. Seed yield was strongly associated with LAI and dry matter accumulation per plant at all the stages.  相似文献   

16.
Particular problems in N fertilization of winter wheat are found in areas characterized by excessive drainage and rainy springs. A two yearly experiment was carried out in such an environment (Udine, northern Italy) with the objective of testing the effect of increasing levels of total N supply (0, 70, 140 and 210 kg ha−1) and of different times of late N side-dressing (at stem elongation, booting or flowering) on yield, quality traits and on N use efficiency of the wheat cv. Saliente.
The results obtained indicated that yields of about 5 t ha1 can be obtained if the N supply permits a crop recovery of 130-140 kg ha−1. Supplying the last N fraction at booting increased the fertility of the spike, the overall quality of the product and the efficiency of the fertilization. N supply can be delayed to flowering time in case of high total N, with further positive effects on the quality of the product. The nitrogen use efficiency was inversely and linearly related to total N supply.  相似文献   

17.
A field expenment was conducted during 1992–94 at CIMAP, Field Station, Bangalore, India to study the effect of depth (25, 37.5 and 50 mm) and methods (Ridge and furrow and Broad Bed and furrow method) of irrigation and nitrogen levels (0, 200 and 400 kg N ha−1 year−1) on herb and oil yields of Java citronella. At the highest level of N application (400 kg N ha−1 year−1) ridge and furrow method was better suited for irrigating citronella. However, under lower N levels (0 and 200 kgN ha−1 year−1), as much as 30 % water can be saved by the broad bed and furrow method. The results have shown that highest herb and oil yields of citronella were achieved with the application of 400 kg N and maintaining 25 mm depth of irrigation. Content and quality of oil were not affected either by irrigation or nitrogen.  相似文献   

18.
The effect of fungicides and their combination on yield of barley under different nitrogen, slurry and tillage treatments was investigated at Hohenschulen Experimental Station near Kiel, Germany in 1991–97. Various fungicide treatments (no fungicide, and treatment with stem, leaf and ear fungicides and combinations of these), two nitrogen levels (120 and 240 kg N ha−1), two tillage systems (minimum and conventional tillage) and four slurry applications (no application, and autumn, spring and autumn plus spring applications) were used. On average, fungicide application increased barley yield by 1.1 t ha−1. The fungicide treatments could be classified into four types: (1) fungicides against stem diseases, which slightly increased yield by 0.25 t ha−1, very similar to the results for the untreated control; (2) leaf fungicides and ear fungicides applied separately, and fungicides against a combination of stem and leaf diseases, which increased yield by 1.0 t ha−1 on average; (3) fungicides against a combination of ear and stem diseases, which increased the yield by 1.22 t ha−1, and (4) fungicides against a combination of leaf and ear diseases and a combination of stem, leaf and ear diseases, which increased yield by 1.59 t ha−1 on average. The effects of fungicide on the yield were modified by crop husbandry. It can be concluded that application of fungicides against a combination of leaf and ear diseases could increase barley yield and reduce yield variation.  相似文献   

19.
任慧  丁磊  赵财 《中国农学通报》2021,37(35):57-64
风蚀是干旱区农田生态系统中土壤质量降低的关键因素,冬季作物覆盖可有效减少农田的土壤风蚀。通过探究河西灌区不同冬季覆盖作物轮作复种绿肥对农田土壤碳氮影响,以期为构建合理的周年覆盖轮作模式提供理论依据。本研究在热量一熟有余两熟不足的河西灌区春小麦种植区把冬小麦、冬油菜两种冬季覆盖作物和绿肥还田处理嵌套种植形成：（1）春小麦—冬油菜—箭筈豌豆(WCP)、（2）春小麦—冬小麦—箭筈豌豆(WWP)、（3）春小麦—箭筈豌豆(WP)、(4)春小麦—春小麦(W,CK)不同种植模式,在360 kg/hm2 (N2)、270 kg/hm2 (N1)、0 kg/hm2 (N0) 3个施氮水平下,研究不同轮作模式对农田土壤碳、氮含量的提升效应。结果表明：在同一种植模式下土壤有机碳、土壤可溶性有机碳、热提取态有机碳、硝态氮、氨态氮、微生物量碳氮含量随施氮量的增加而增加,但在氮肥减量(N1)的条件下,与常规施氮(N2)相比较WCP轮作模式土壤有机碳、土壤可溶性有机碳、热提取态有机碳含量及微生物量氮无显著降低。相同施氮条件下,轮作模式间差异不显著,但与CK间差异显著;其中,0~10 cm土层,WCP轮作模式土壤有机碳、土壤可溶性有机碳、土壤热提取态有机碳、硝态氮、氨态氮、微生物量碳氮含量平均较CK提高5.42%、9.78%、10.96%、20.51%、15.76%、18.94%;10~30 cm土层,提高9.54%、7.06%、12.99%、20.12%、16.51%、18.16%。因此,春小麦轮作冬油菜复种绿肥模式在氮肥减量条件下仍对农田土壤碳氮有明显的提升效应,为河西灌区良好的周年覆盖作物轮作模式。  相似文献   

20.
The effects of nitrogen and sulphur on the yield and fatty acid composition of mustard ( Brassica juncea L.) oil were studied in a field experiment. Significantly higher grain and oil yields were obtained with N and S application. Applications of nitrogen up to 60 kg ha−1 and sulphur up to 40 kg ha−1 favourably influenced the grain yield. Increasing levels of N decreased the oil content while application of sulphur improved the oil content. The contents of linoleic and linolenic acid were maximum (16.82 and 8.73%, respectively) with 60 kg N along with 40 kg S ha−1. No use of fertilizers led to higher contents of undesirable fatty acids such as palmitic (hypercholesterimic) and erucic (do not have food value) acids.  相似文献   

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