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1.
In a soil lacking indigenous Bradyrhizobium japonicum , soybean ( Glycine max [L.] Merr.) nodulation depends upon the number of rhizobia applied with the inoculum. This field study reports the effect of different rates of applied rhizobia on nodulation, dry matter and nitrogen content in soybean in a Mediterranean soil lacking B. japonicum.
Treatments included six rates of B. japonicum , ranging from 2.5 × 104 to 6.075 × 106 rhizobia cells per seed applied to the seed as peat inoculant at planting, 100 kg N ha−1 and an uninoculated control. The experiment was conducted in an Entisol soil. Regression analysis showed linear relationship between the rate of applied rhizobia and the number of the nodules per plant or the dry weight per nodule. In early stages of development (32 and 68 days after planting) plant dry weight was not affected by inoculation rate. At harvest a rate of 7.5 × 104 rhizobia cells per seed was necessary for maximum total and stover dry weight. A higher rate, 6.75 × 105 rhizobia cells per seed, was required to obtain maximum grain yield, total N content in plant tops and grain N content. Grain percentage N was increased up to 2.025 × 106 rhizobia cells per seed. Nitrogen application increased grain yield, total N content and grain N content at the same level as the lower inoculation rate.  相似文献   

2.
A field experiment was conducted for 2 years during 1991–93 at the Central Institute of Medicinal and Aromatic plants, Bangalore, India to study the effect of plant spacings (60 × 60, 60 × 45, 60 × 30 and 45 × 45 cm) and nitrogen levels (0, 50, 100 and 150 kg N ha−1 year−1) on growth, herb and oil yield of lemongrass. A closer plant spacing of 45 × 45 cm resulted in higher herb and oil yields compared to wider spacing of 60 × 60 cm. Application of 150 kg N ha−1 year−1 resulted in higher herb and oil yields. Higher nitrogen applications also increased the plant height and number of tillers per clump. The oil content and quality-was not influenced by spacing and nitrogen levels.  相似文献   

3.
Growth and yield responses to plant density (6.75 × 104, 9.75 × 104 and 12.75 × 104 plants ha–1) and stage of transplanting (30, 35 and 40 days after sowing) of winter oilseed rape cultivar HO 605 were investigated in two field trials in the 1996/97 and 1997/98 growing seasons at Zhejiang University Farm, Huajiachi Campus, China. Results revealed a progressive decrease in leaf area per plant in response to increasing plant density and delayed transplanting, though leaf area m–2 and leaf area index were higher in high-density plants. Number of effective branches and pod per branch decreased with increasing plant density and delayed transplanting. There were no significant differences in the mean seed weight among treatments. Although the average number of seeds per pod was significantly lower for high-density plants and delayed transplanting, the economically highest seed yields were realized in relatively high-density plants. Seed oil content was negatively affected by increasing plant density, but no significant differences were observed with delayed transplanting. The highest seed yields of 1730.7 and 1748.1 kg ha–1 with no significant differences were observed for plant densities of 9.75 × 104 and 12.75 × 104 plants ha–1, respectively, transplanted at 35 and 30 days after sowing.  相似文献   

4.
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   

5.
Little is known about the effect of fertilization on the P uptake of sunflowers. A 42 factorial trial with 0, 60, 120 and 180 kg N ha−1 and 0, 15, 30, and 45 kg P ha−1 was conducted over three years. The P content and concentration of leaves, stems and capitula were determined at three growth stages. High N levels increased the P content and concentration of all plant components in early growth stages only. High P levels increased the P content and concentration of all plant components sharply almost throughout. Plants seem to recover some lost growth towards the end of the season so that at physiological maturity there are no significant differences in P content among N levels. The translocation of P from the stems is very effective but P can accumulate in the leaves if a luxury quantity of P is present in the plants. In terms of seed yield a significant N × P interaction was found, indicating a sharp response to both N and P only in the presence of a sufficient quantity of the other element. The response of seed yield was in agreement with the P absorption by the plants.  相似文献   

6.
A simple randomized field experiment was conducted to assess the growth and yield of rape-seed-mustard in relation to sulphur and nitrogen interaction. Three levels of sulphur (0, 40 and 60 kg ha−1) in combination with three levels of nitrogen (60, 100 and 150 kg ha−1) were tested as treatments, T1, T2, T3, T4, and T5. Results indicated significant favourable effects of sulphur and nitrogen, when applied together, on yield components, seed and oil yield. Maximum response was observed with treatment T3 (having S and N of 40 and 100 kg ha1, respectively). Percentage oil content of seed was maximal at T4 (having S and N of 60 and 100 kg ha1) in both cultivars. The increase in N dose from 100 to 150 kg ha−1 without any change in applied S, i.e. 60 kg ha1 (T5), decreased the percentage oil content. The seed and oil yield, however, were similar to T3. Favourable responses of S and N interaction on leaf area index, rate of photosynthesis and biomass production were also observed.  相似文献   

7.
Two field experiments were conducted during] 994-95 to study the effect of spray of 10−5 M GA3 at 40 days after sowing on mustard ( Brassica juncea (L.) Czern & Coss.) cv. Varuna grown with basally applied 0, 40, 80 and 120 kg N ha−1 (Expt. 1) and 0,15, 30 and 45 kg P ha−1 (Expt. 2) on pod number per plant, seeds per pod, 1000 seed weight, seed yield, biological yield, harvest index and fatty acid composition of oil. No significant difference between water and GA3 spray was found when basally applied nitrogen was 0 or 40 kg N ha−1. N80 proved to be the best for yield characteristics. In another experiment on phosphorus, GA3 and 30 kg P ha−1 individually enhanced the yield, but interaction of GA3 and P remained non-significant. The fatty acid composition of oil in both experiments was significantly affected only by nitrogen and phosphorus treatments for oleic acid and erucic acid. It was found that return in the form of yield was more for every kg applied fertilizer under GA, spray treatment. The response was more for N fertilizer in comparison to P. GA3 at a low level of fertilization significantly increased the return from fertilization.  相似文献   

8.
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   

9.
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   

10.
In a field trial conducted during 1992–93 and 1993–94, the effect of basal (B) nitrogen (N) (45 and 60 kg N ha−1) and foliar application (F) of water (W) or 10 kg N ha−1 and 400 or 600 ppm ethrel (E) (2-Chloro ethyl phosphonic acid) at 70 days after sowing was studied on leaf area index and dry mass at 90 days and pod number per plant, seeds per pod, 1000 seed weight, seed yield, oil content and oil vield at harvest of mustard ( Brassica juncea L. Czern & Coss.) cv. T-59. Recommended basal (B) application of 90 kg N ha (BN90) was used as control. On the basis of 2 year data it was found that basal application of 60 kg N and foliar spray of 10 kg N ha −1 and 600 ppm ethrel gave higher values for growth and yield characteristics and enhanced seed yield and oil yield by 12.5 and 14.8%, respectively over control BN90.  相似文献   

11.
The effects of planting date and plant density on potassium (K) and magnesium (Mg) uptake and harvest by Brussels sprouts ( Brassica oleracea var. gemmifera ) were studied in field experiments. Crop potassium concentration generally decreased towards harvest, but the pattern in potassium concentration during crop growth differed between planting dates. Plant density in the range of 2.7–4.4 plants m−2 had no effect on crop potassium concentration. The amount of potassium in the crop at harvest decreased with a delay in planting, but was not influenced by plant density. Mainly depending on the planting date, around 100–200 kg potassium ha−1, or approximately 40–50 % of the potassium in the crop at harvest, is removed from the field with the product. Averaged over treatments and years, potassium concentration in the (fresh) product was 5.2 kg ton−1. The amount of magnesium in the crop at harvest decreased with a delay in planting. Depending on the planting date, uptake at harvest was 10–17 kg magnesium ha−1. Plant density had no effect on this amount. On average per ton (fresh) product, 0.20 kg of magnesium was removed from the field.  相似文献   

12.
Little is known about the effect of fertilization on the N uptake of sunflowers. A 42 factorial trial with 0, 60, 120 and 180 kg N ha−1 and 0, 15, 30 and 45 kg P ha−1 was conducted over three years. The N content and concentration of leaves, stems and capitula were determined at three growth stages. High N levels increased the N content and concentration of all plant parts at all growth stages sharply. High P levels increased the N content of all plant components through better growth. P has an inconsistent effect on N concentration but tended to decrease it. After flowering the crop assimilated 20 to 25 % of the total N. This implies that N applied can still be applied and utilized by the crop at a late stage. This should be substantiated by further research.  相似文献   

13.
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   

14.
Field experiments were conducted during the wet seasons of 1991,1992 and 1993 at the Abubakar Tafawa Balewa University Farm, Bauchi (10 ° 22'N, 09 ° 47'E) to study the response of sunflower ( Helianthus annaus L.) to N rates and plant population under rainfed conditions. Four N rates (0, 50, 100 and 150 kg N ha -1) and four plant populations (40000,80000,120000 and 160000 plants ha-1) were factorially combined in a randomized complete block design with three replications. Leaf area index, shoot dry weight and seed yield (kg ha-1) increased significantly with increasing N rates from 0 to 100 kg N ha-1. The growth and yield parameters per plant decreased significantly with increasing plant populations from 40000 to 160000 plants ha-1, but the seed yield (kg ha-1) obtained at 80000 plants ha-1 was significantly higher than all the other plant populations. The interactions of N x plant population confounded the main effect of each factor on the growth and yield of sunflower. The seed yield (3425 kg ha-1) obtained from the use of 100 kg N ha-1 at 80000 plants ha-1 was significantly higher than those obtained from all other combinations of N x population and out-yielded the main effects of 100 kg N ha-1 and 80000 plants ha-1 by 18 % and 25 %, respectively. The use of 100 kg N ha-1 at 80000 plants ha-1 is therefore recommended for maximum yield of sunflower in Bauchi.  相似文献   

15.
In potato, dry matter (DM) production and partitioning between plant organs and N accumulation are affected by N application; however, since cultivars differ in these processes, N fertilization must be adjusted to each cultivar. This paper studies the response of potato cultivars differing in maturity to N fertilization in the south-east of the Buenos Aires Province (37°45'S, 58°18'W) in two growing seasons. Treatments combined four N doses (0–180 kg ha−1) and four cultivars: Jaerla (early), Spunta (mid-early), Mailén INTA (medium late) and Huinkul MAG (late). DM and N content were measured in leaves, stems and tubers throughout the growing season and intercepted photosynthetically active radiation was regularly assessed. There was an increase in tuber yield up to intermediate N doses (60 kg ha−1 in 1990 and 120 kg ha−1 in 1991). Tuber yield was similar for Spunta and Huinkul MAG. There was no interaction between cultivar and N fertilization for tuber dry matter yield. DM partitioning to leaves and tubers during the growing season differed among cultivars, but N availability affected partitioning similarly for all cultivars. Jaerla had a high and Huinkul MAG had a low radiation use efficiency between plant emergence and the beginning of tuber formation. Jaerla, Spunta and Mailén INTA reached maximum N content in foliage at ≈60 days after emergence and Huinkul MAG 20 days later. Total N content at maturity varied between 120 and 250 kg ha−1 and was affected by cultivar and N dose. The results will help to improve N fertilization recommendations and management practices as related to each cultivar under the environmental conditions of this region.  相似文献   

16.
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   

17.
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   

18.
A simple randomized field experiment was conducted for two years to test the comparative efficacy of three sources of leaf-applied phosphorus (sodium dihydrogen orthophosphate, diammonium phosphate and monocalcium superphosphate) on the yield performance of mustard ( Brassica juncea L. Czern. and Coss.) var. Varuna. The quantity of P was 3.5 kg ha−1. In addition, 20 kg N and 2 (or 6) kg S ha−1 were included in the spray applied in two equal splits at 70 and 90 days as supplement to the basal application of 60 kg N, 17.5 kg P and 33.2 kg K ha−1. The two-year data revealed that spray treatments were significantly efficacious in augmenting most of the yield attributing parameters as well as seed and oil yield by about 20% over the water-sprayed control. However, as the three sources of phosphorus proved equally effective, commercial grade monocalcium superphosphate could be preferred over others due to its cost effectiveness and easy availability.  相似文献   

19.
15N-aided investigations were conducted to ascertain the Nj fixation and the nitrogen (N) contribution by mungbean ( Vigna radiata L.) and groundnut ( Aracbis hypogaea L.) when intercropped with maize ( Zea mays ). The study involved growing seven genotypes of the above legumes with maize in alternate rows in two separate experiments. A sole crop of maize was used as the reference crop to determine N2 fixation by the 15N methodology. Significant genotypic differences in pod yield and stover N content were observed in intercropped mungbean and groundnut. The percentage N derived from the atmosphere showed a genotypic variation of 31 to 45 % (7 to 10 kg N2 fixed ha−1O in mungbean and 47 to 69 % (9 to 18 kg N2 fixed ha−1) in groundnut. Harvest index for N varied from 58 to 77 % in mungbean and 55 to 75 % in groundnut. In groundnut, the uptake of soil N was significantly affected by the genotype. Assuming that the N contribution to the soil by the helow-ground plant parts was negligible, the removal of seeds at maturity resulted in a negative N balance in the soil in all the genotypes of mungbean. In groundnut, some genotypes produced a positive N balance in the soil. Owing to high N2 fixation capacity and low harvest index for N, groundnut showed a greater N supplementing ability than mungbean.  相似文献   

20.
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   

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