共查询到20条相似文献,搜索用时 31 毫秒
1.
Summary Dry-matter accumulation, and concentration and uptake of nitrogen increased with increasing level of nitrogen at all the stages of crop growth. The differences in nitrogen concentration due to nitrogen levels were greatest at panicle initiation stage and started becoming narrower with the advancement in crop age. Split application of nitrogen with its heavier fractions at tillering and panicle initiation stages either through soil alone or soil+foliage (1/3+1/3+1/3) resulted in higher dry-matter accumulation, and higher nitrogen concentration and uptake than other methods. The crop, on an average, removed 61 kg N/ha. Plants accumulated nearly 15% of the total absorbed nitrogen, up to tillering, 50% up to panicle initiation and 85–90% up to heading. Proportionately lesser nitrogen uptake and dry-matter accumulation at post-heading stage is an indicative of a major constraint for production efficiency of rainfed-upland rice culture. 相似文献
2.
Patrick H. Brown Steven A. Weinbaum Geno A. Picchioni 《Trees - Structure and Function》1995,9(3):158-164
The influence of alternate bearing on nutrient utilization and total tree nutrient content was investigated in mature pistachio
(Pistacia vera L. cv Kerman trees). Removal of N, P and Zn in fruit and abscised leaves of cropping (‘on’) trees averaged 5, 6, and 2 times,
respectively, the removal in abscised leaflets of the non-fruiting, ‘off’ year trees. One hundred and thirty-five kg N, 131
kg K, 86 kg Ca, 39 kg Mg and 18 kg P per hectare were removed in fruits and abscised leaves in ‘on’ year trees. Tree nutrient
contents and, presumably, the size of nutrient storage pools in dormant trees varied between ‘on’ and ‘off’ years. There was
22% and 14% more N and P, respectively, in dormant trees following ‘off’ than ‘on’ years. The greater N and P accumulation
in ‘off’ year trees is depleted in support of the large fruit demand for N and P during ‘on’ years. In contrast to N and P,
there was greater K and Ca accumulation in perennial tree parts during ‘on’ years than during ‘off’ years. The greater K accumulation
in perennial tree parts and approximately 30% greater removal of K in annual organs during ‘on’ than ‘off’ years suggests
that K uptake could be 4 times higher in ‘on’ year trees than in (non-cropping), ‘off’ year trees. 相似文献
3.
Summary A laboratory study was made of the losses of nitrogen through ammonia volatilization from four flooded, tropical soils. The
soils used varied considerably in pH, organic matter content, and cation exchange capacity. Losses were measured from the
unamended soils, and from ammonium sulphate and urea-treated soils. Two rates of nitrogen application (approximately 50 and
200 kg/ha N) and two methods of application (simulated field broadcast and fertilizer incorporation) of the nitrogen were
used.
Losses of ammonia were detected for each of the unamended soils, including an acid sulphate soil of pH 3.6. Increased application
of both ammonium sulphate and urea resulted in increased losses of ammonia through volatilization. Incorporation of the nitrogen
into the mud of the flooded soils significantly decreased losses due to volatilization. It was concluded that the initial
or ‘aerobic’ pH of the soils was the soil characteristic most closely related to the magnitude of losses due to volatilization. 相似文献
4.
Y. P. Kalra 《Plant and Soil》1971,34(1):535-539
Summary Isotopic-dilution technique was used to study the differential phosphate absorption abilities of several field crops. The
response of crops was found to be inversely related to the ratio of phosphorus absorbed from the soil to that absorbed from
the fertilizer. The ‘A’ values ranged from 2.03 ppm for mustard to 21.77 ppm for soybeans. A highly significant correlation
(r=0.77**) was found between per cent yields and the ‘A’ values. 相似文献
5.
A. H. Price A. D. Tomos D. S. Virk 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(1-2):132-142
Root growth is an important component of the adaptation of rice to drought-prone environments. A hydroponic screen was used
to study root growth of 28 rice varieties. Both maximum root length and adventitious root thickness varied widely between
varieties. In general, japonica varieties had larger root systems than indica varieties. Two F2 populations involving the thick- and long-rooted upland japonica variety ‘Azucena’ and two poor-rooting varieties, namely the upland indica‘Bala’ and the Italian japonica‘Maratelli’, were made and screened in hydroponics. Generation means analysis revealed significant additive and dominance
main effects for the root length traits with a prevalence of dominance gene effects in both crosses. The dominance×dominance
type of non-allelic interactions were important for maximum root length from day 7 to day 28, root volume, root thickness
and root cell length in the cross ‘Bala’בAzucena’. The heritability (broad-sense) estimates varied from low to high for the
traits and displayed differences between populations. This suggested that recombinant lines with improved root traits can
be developed from the two crosses with selection methods that involve some form of progeny evaluation. In a companion paper,
we report the mapping of quantitative trait loci (QTLs) for root growth traits in the ‘Bala’בAzucena’ population using restriction
fragment length polymorphisms (RFLPs).
Received: 5 May 1996 / Accepted: 14 February 1997 相似文献
6.
Combined inoculation of Rhizobium and ‘Phosphate-solubilizing’Pseudomonas striata orBacillus polymyxa with and without added chemical fertilizer on chickpea yield and nutrient content was studied under greenhouse conditions.
While the single inoculation of Rhizobium increased the nodulation and nitrogenase activity, the ‘phosphate-solubilizers’
increased the available phosphorus content of the soil. Combined inoculation of Rhizobium andP. striata orB. polymyxa increased the above parameters and also the dry matter content, the grain yield and nitrogen and phosphorus uptake significantly
over the uninoculated control. The inoculation effects were more pronounced in the presence of added fertilizers. The possibilities
of saving half the dose of N and replacing superphosphate with rockphosphate and inoculation with ‘phosphate-solubilizers’
are discussed. 相似文献
7.
Summary A study was conducted on the quantities of crop residues (stubbles) recycled into the soil after harvest with 2 early and
3 medium duration varieties of rice under irrigated culture. The addition of crop residues depended linearly on the total
dry matter production of the plants. Dry matter (DM) of stubbles and the N content of the same showed a linear trend. The
relationship between grain yield and N contribution through stubbles fitted to a linear regression. In early types the maximum
N recycled is 16 kg/ha at an yield range of 4 to 6 t/ha while in medium types a maximum of 26 kg N/ha is recycled at the same
yield level. The relationships between DM of stubbles and ‘P’ content of the stubbles and between grain yield and ‘P’ content
of stubbles also turned out to be linear. The P content varied from 1 to 4 kg/ha in early types and 1 to 2 kg/ha in medium
group. More N was recorded in the stubbles of the medium group while more P was found in the early duration varieties. There
were clear varietal variations and the results were discussed in the light of the current literature. 相似文献
8.
Summary The composition of the leachate from undisturbed monolith lysimeters cropped with white clover or meadow fescue or maintained
bare was compared with that of the rain falling on them. No nitrogen fertilizer was applied only an initial dressing of phosphorus
and potassium. The grass received much more nitrogen from the rain than it lost by leaching whereas the clover lost more than
it received. Most of the leached nitrogen was NO3-N - 92 per cent on the bare soil and 90 per cent on the clover. About 27lb nitrogen per acre (30 kg/ha) per year was drained
from the actively growing clover sward rising to about 117lb N/acre/year (131 kg/ha) when the clover died or was removed.
Only 2.3lb/ac (2.5 kg/ha) was drained from the actively growing grass sward. It was estimated that the clover fixed at least
270lb N/ac/year (303 kg/ha/year. The rates of leaching of potassium from a grass sward was about 1.7lb/ac/year (1.9 kg/ha)
and 0.8 lb (0.9 kg) phosphorus. The quantities were similar for clover. The grass received from the rain more phosphorus and
potassium than was leached but only 60 per cent of the calcium and 13 per cent of the magnesium, similar results being obtained
with white clover.
During the year of establishment of the grass sward there was evidence of loss of gaseous nitrogen (elemental and/or compound)
from the soil: subsequently the nitrogen content of the soil slowly increased. Calcium loss from the bare soil with an average
rainfall of 26″ (650 mm) was about 100 lb Ca/ac/year (112 kg/ha). 相似文献
9.
Summary Differences in the productivity of establishedP. radiata plantations on pasture and forest soils were found to be reproducible withP. radiata seedlings in a glasshouse environment. The growth of seedlings on pasture soil exceeded that of seedlings on native forest
soil (the ‘primary pasture effect’). After a history of pine on both native and pasture soils a residual effect of pasture
on seedling growth was evident (the ‘secondary pasture effect’). However, the effect of a history of pine plantation (the
‘pine effect’) was to decrease the productivity of both native and pasture soil as assessed by seedling growth. These effects
were not related to changes due to land management in mycorrhizal infection or in soil structure. The analysis of seedling
growth leads to the conclusion that soil fertility, particularly the availability of nitrogen and phosphorus, has changed. 相似文献
10.
Summary A field experiment was designed to determine the salt tolerance of three varieties of sweet pepper for paprika, studying the
effects of four increasing levels of sodium chloride in the irrigation water (5, 10, 29 and 42 meq/l) on soil salinity, yields,
and quality of the fruits.
EC5:1 and the soluble sodium and chloride contents increased with increasing salinity. The yields were reduced by 5 per cent for
variety ‘Ramillete’, 19 per cent for ‘Tres cascos’, and 40 per cent for ‘Bola’ at the highest level. The fruit quality variables
studied (colour index and chloride contents) differed with the variety. re]19750925 相似文献
11.
Muhammad Iqbal Chaudhary Joseph J. Adu-Gyamfi Hirofumi Saneoka Nguyen Tran Nguyen Ryuichi Suwa Shynsuke Kanai Hany A. El-Shemy David A. Lightfoot Kounosuke Fujita 《Acta Physiologiae Plantarum》2008,30(4):537-544
Phosphorous (P) fertilization is the major mineral nutrient yield determinant among legume crops. However, legume crops vary
widely in the ability to take up and use P during deficiency. The aim here was to compare P uptake and translocation, biological
nitrogen fixing ability and photosynthetic rate among mashbean (Vigna aconitifolia cv. ‘Mash-88’), mungbean (Vigna
radiata cv. ‘Moong-6601’) and soybean (Glycine max L. cv. ‘Tamahomare’) during deficiency in hydroponics. Two treatments, the withdrawal of P from the solution (P-deprivation)
and continued P at 160 μM (P sufficient) were effected at the pod initiation stage. Plants were grown for 20 days. Short-term
labeling with 32P showed the uptake and distribution of P into plant parts. Withdrawal of P from the solution reduced biomass, photosynthetic
activity, and nitrogen fixing ability in mungbean, and mashbean more than in soybean. P deprivation decreased P accumulation
more than N accumulation. The decrease was more severe in mungbean and mashbean than soybean. More P was translocated and
distributed into leaves in soybean than in mungbean and mashbean. Leaf P amount was more correlated to leaf area than to photosynthetic
rate per unit leaf area among all three legume species. The results indicate that selection for increased efficiency of P
utilization and leaf area may be used to improve leguminous crops. 相似文献
12.
Summary Field experiment was conducted during 1980–81 on the Indo-Gangetic alluvial soil of Pura, Kanpur to study the effects of added
potassium and zinc on dry-matter production and uptake of these nutrients by potato crop. Increasing supply of potassium and
zinc significantly increased the dry-matter production and concentration and uptake of respective nutrients in different crop
components. The effects of combined application of potassium and zinc was positive in influencing the dry-matter production
and K, Zn uptake by potato crop. Increasing supply of potassium showed beneficial effect on the absorption and translocation
of zinc in plant system indicating thereby greater utilization of fertilizer zinc by the crop. Increasing supply of zinc,
however, could not influence the concentration of potassium. 相似文献
13.
Summary The effect of soaking seed tubers in P solution on tuber yield, P uptake and fertilizer economy was investigated on acid brown hill soil and alluvial soil from 1972 through 1975. Nondormant whole seed tubers soaked in 0.4 percent P solution of mono- and diammonium phosphate and of filtered superphosphate increased tuber yield and P uptake. The effect of the soaking on increasing the P composition of seed tubers was most pronounced in the case of monoammonium phosphates solution. Cut seed tuber pieces absorbed more P than the whole seed tubers. On highly P-deficient acid brown hill soil, soaking affored to economise on P application by about 25 kg P2O5/ha, applied to soil whereas on marginally deficient alluvial soil, a soaking treatment was adequate and obviated the need of soil application of P. 相似文献
14.
Legumes as ground cover are regularly planted to increase nitrogen economy of crops and to improve soil. In the present study
various clover species were evaluated as vegetative ground cover in nursery field production of micropropagated red birch
(Betula pubescensEhrh. f. rubraUlvinen f. nova) in two 2-year experiments. The clover species and cultivars, Trifolium pratenseL. ‘Bjursele’, T. repens L. ‘Jogeva’, T. repens L. ‘Sonja’, T. hybridum L. ‘Frida’, T. incarnatum L. ‘Opolska’, T. resupinatum L. and T. subterraneum L. were compared to grass sod Festuca rubra L. ‘Ensylva’ and to a coverless ground (control). The last one was kept weed free by hand hoeing. Birch (leaves, stems, branches
and roots) and soil nutrient concentrations (N, P, K, Ca, Mg and Fe) were analysed and nutrient ratios in birch determined.
The annual clovers, T. incarnatumL., T. resupinatumL. and T. subterraneumL., provided about the same nutrient status in birch as did the control. Perennial clovers and grass were strong competitors
with trees. High levels of P and Mg in birch leaves relative to N concentration were typical for poorly growing seedlings.
Neither annual nor perennial clovers did generally improve soil nutrient status.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
15.
Pieter Pypers Liesbeth Van Loon Jan Diels Robert Abaidoo Erik Smolders Roel Merckx 《Plant and Soil》2006,283(1-2):251-264
There are several indications that legumes are capable of accessing sparingly soluble phosphorus (P) in the soil through root-induced
processes. We hypothesize that this plant-induced mobilization of P can be demonstrated if the plant accessible P assessed
by isotopic dilution (‘L-value’) exceeds the corresponding values assessed in soil extracts (‘E-values’). A greenhouse experiment was set up to assess if L/E ratios are affected by P supply and by crop type. The L- and E-values were determined in three P-deficient soils of the Nigerian Northern Guinea savanna (NGS), applied with various rates
of TSP, for two cowpea varieties (Vigna unguiculata L., cv Dan-Ila and cv IT-82D-716) and maize (Zea mays L., cv oba super I) as a reference. Plants grown in control soils were severely P-deficient. Plant growth and shoot P uptake
significantly increased with increasing P application in all three soils and for all crops, but relative yield and shoot-P
responses to P application were similar between maize and cowpea. Both L- and E-values increased with increasing P application. Average L/E ratios for maize were 1.4±0.3 and were unaffected by the P application.
For cowpea in contrast, L/E ratios were 3.1±0.2 (significantly larger than one) in one of the three control soils and significantly
decreased to 1.3±0.1 at largest P supply. Elevated L/E ratios in cowpea were not associated with an increase in P uptake compared
to the other two control soils in which no increase in L/E ratio was observed. It is concluded that cowpea is able to access
non-labile P under P-deficient conditions. However, this process cannot overcome P deficiency in these soils, probably because
P uptake is limited by the small P concentration in the soil solution (1–2 μg P L−1) and this limitation is not overcome by an increase in the accessible soil P quantity (L-value). 相似文献
16.
Whitbread Anthony Blair Graeme Naklang Kunnika Lefroy Rod Wonprasaid Sodchol Konboon Yothin Suriya-arunroj Duangjai 《Plant and Soil》1999,207(1):29-36
The maintenance of soil organic matter (SOM) and the balancing of nutrient flows into and out of the rainfed rice cropping
systems in Northeast Thailand is of paramount importance to arresting the decline in soil fertility and crop yields. A system
where small applications of leaf litters from locally grown trees are applied annually to rice paddy soils prior to transplanting
is described. The annual application of 1500 kg/ha of Cajanus cajan, Acacia auriculiformis, Phyllanthus taxodifolius and Samanea
saman for five seasons resulted in increases in rice grain yield of 48, 35, 32 and 23% above the no-leaf litter control, respectively.
Average annual nutrient inputs from the leaf litters, in kg/ha, ranged from 62.7 N, 3.9 P, 17.9 K, and 3.5 S for Cajanus cajan
to 24.5 N, 1.5 P, 8.1 K and 2.0 S for Acacia auriculiformis. Nutrient balances, determined by the difference between the inputs
(fertiliser and added leaf litters) and outputs (grain and straw) indicated net positive N and P balances of up to 457 and
60 kg/ha. respectively, after five seasons of leaf litter applications. Sulfur and potassium balances resulted in net deficits
of up to −3 and −52 kg S and K/ha, respectively, where no leaf litter was applied and rice straw was removed following harvest.
Calculated apparent nutrient recoveries reflected the decomposition rate of the added residues and were highest for P and
K, reflecting their higher soil residual value than mobile nutrients such as N and S. Sustainable farming systems will require
that crop yields are stable through the maintenance of soil fertility and the balance of nutrients in the system.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
17.
Drip nitrogen fertigation of ‘Starking Delicious’ apple trees 总被引:2,自引:0,他引:2
The response of ‘Starking Delicious’ (Malus domestica Borkh.) apple trees to four N fertigation treatments in drip irrigation (50, 150, 250 and 400 kg N ha−1, supplemented with a uniform dose of 400 kg K ha−1) was investigated in a field experiment during 6 years.
Nitrate nitrogen in the soil was proportional (7–58 mg kg−1) to the applied N dose at the end of a 6 week fertigation period in the spring. At other times, the nitrate concentration
in the soil was very low. Soil K decreased with depth and in the 0–30 cm soil layer it was negatively correlated with the
applied N dose, before fertigation started. At the end of the spring fertigation period, higher K was found in all soil layers
analyzed.
Vegetative growth was correlated positively with the amount of N applied. Leaf chlorophyll and N were significantly lower
only in the lowest N treatment, while increased fruit size and decreased fruit color were measured only in the higher N treatments.
Yield was severely biennial. In the ‘On’ years crop load was heavier as less N was applied. An extremely high crop load in
the lowest N treatment was followed by a reduced flower density and yield in the following season. In the ‘Off’ years, a significantly
higher yield was obtained with the 150 kg ha−1 dose. The dry weights, N, P and K contents of the above ground parts of mature apple trees were determined.
Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, No. 2342-E, 1988 Series. 相似文献
18.
J. G. Roddick G. Melchers 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1985,70(6):655-660
Summary Analyses of leaves and ‘tubers’ from somatic hybrids of potato and tomato (‘pomato’ with plastids of potato, ‘topato’ with
plastids of tomato) produced by fusion of protoplasts from liquid cultures of dihaploid potato and mesophyll of tomato revealed
the presence of the two major potato glycoalkaloids (α-solanine and α-chaconine) as well as the tomato glycoalkaloid (αtomatine). The total alkaloid content of leaves was greater than that of ‘tubers’ and similar to levels in the foliage of
parent plants. However, glycoalkaloids were more abundant in hybrid ‘tubers’ than in normal potato tubers by a factor of 5–15.
In hybrid foliage, approximately 98% of the alkaloid present was of potato origin whereas in ‘tubers’ the reverse was the
case, with tomatine comprising 60–70% of the total alkaloid. The similarities in alkaloid content and ratios between the pomato
and the topato lines indicate that plastomes do not influence the biosynthesis and distribution of these alkaloids. The results
indicate that major secondary metabolites may prove useful for assessing the hybrid nature of such plants. 相似文献
19.
Root growth,macro-nutrient uptake dynamics and soil fertility requirements of a high-yielding winter oilseed rape crop 总被引:2,自引:0,他引:2
P. B. Barraclough 《Plant and Soil》1989,119(1):59-70
Shoot growth, root growth and macro-nutrient uptake by a high-yielding (5t/ha grain) winter oilseed rape crop have been measured.
Maximum rooting density in the top 20cm of soil was 9.4 cm cm−3 and roots reached a depth of at least 1.8 m. Maximum nutrient uptakes were 364 kg ha−1 for N, 43 kg ha−1 for P, 308 kg ha−1 for K, 287 kg ha−1 for Ca and 16 kg ha−1 for Mg. A 30-day drought coincided with the flowering period and root and shoot growth, as well as nutrient uptake rates,
were reduced. Nutrient concentrations in the soil solution necessary to sustain the nutrient fluxes into the root system by
diffusive supply have been calculated. Peak values were in the range 10 μM for P to 87 μM for N, lower than the observed concentrations, and it was concluded that nutrient transport to roots was not a limitation
to uptake by this rape crop. 相似文献
20.
B. F. Bland 《Plant and Soil》1968,28(2):217-225
Summary and conclusions 1. Possible sources of free nitrogen are enumerated and evaluation has been attempted in respect of a West of Scotland soil.2. The total annual contribution of nitrogen to the soil from all free sources could be of the order 100–120 lb N per acre (=101–130 kg N per ha).3. Assuming that two thirds of this is harvestable in grassland then 66–80 lb N may be expected in the absence of added fertilizer nitrogen.4. The observed value for the nitrogen uptake by the grass component in a mixed sward (perennial ryegrass and white clover) in its third year (1965) amounted to 66 lb/N/acre.5. The uptake of nitrogen by perennial ryegrass grown alone without added fertilizer amounted to 89 and 65 lb in 1964 and 1965 respectively. These results corroborate the values for estimated nitrogen contribution outlined in (3) above and also agree well with the experimental findings of (4).6. Since the amount of nitrogen in the grass monoculture was similar to that obtained by the grass when grown in association with clover (1965 Data) it would therefore indicate that white clover did not materially affect the nitrogen uptake by perennial ryegrass. 相似文献