scholarly journals Effect of ammonium and nitrate source of nitrogen on productivity of photosynthesis in Scots pine (Pinus silvestris L.) seedlings

2015 ◽  
Vol 42 (4) ◽  
pp. 599-605 ◽  
Author(s):  
A. Łotocki ◽  
W. Żelawski

Water culture and sand culture seedlings of Scots pine were investigated in respect to their reaction to ammonium or nitrate source of nitrogen nutrition. Photosynthesis, respiration, and dry matter production were studied in three and four months old plants. The results are preliminary but they have indicated that the effect of various form of nitrogen nutrition on gas exchange and growth rates could change during the growing season.

2015 ◽  
Vol 42 (4) ◽  
pp. 607-615 ◽  
Author(s):  
J. Zajączkowska

he reaction of Scots pine (<i>Pinus silvestris</i> L.) seedlings to ammonium and nitrate form of nitrogen was investigated. Rates of photosynthesis and respiration, content of chlorophylls, and accumulation of organic substance were determined in 12 and 18 weeks old plants. The results have shown, that the forms of nitrogen does affect the amount of accumulated organic substance as well as its distribution in particular organs.


2010 ◽  
Vol 61 (5) ◽  
pp. 353 ◽  
Author(s):  
L. L. Burkitt ◽  
D. J. Donaghy ◽  
P. J. Smethurst

Pasture is the cheapest source of feed for dairy cows, therefore, dairy pastures in Australia are intensively managed to maximise milk production and profits. Although soil testing commonly suggests that soils used for dairy pasture production have adequate supplies of phosphorus (P), many Australian dairy farmers still apply fertiliser P, often by applying smaller rates more frequently throughout the year. This study was designed to test the hypotheses that more frequent, but lower rates of P fertiliser applied strategically throughout the growing season have no effect on dry matter production and P concentration in perennial ryegrass (Lolium perenne L.), when soil extractable P concentrations are above the critical value reported in the literature. Three field sites were established on rain-fed dairy pasture soils ranging in P sorption capacity and with adequate soil P concentrations for maximising pasture production. Results showed that applied P fertiliser had no effect on pasture production across the 3 sites (P > 0.05), regardless of rate or the season in which the P was applied, confirming that no P fertiliser is required when soil extractable P concentrations are adequate. This finding challenges the viability of the current industry practice. In addition, applying P fertiliser as a single annual application in summer did not compromise pasture production at any of the 3 sites (P > 0.05), which supports the current environmental recommendations of applying P during drier conditions, when the risk of surface P runoff is generally lower. The current results also demonstrate that the short-term cessation of P fertiliser application may be a viable management option, as a minimal reduction in pasture production was measured over the experimental period.


1971 ◽  
Vol 49 (3) ◽  
pp. 353-358 ◽  
Author(s):  
Klaus Steinbeck

Four random clones of American sycamore supplied with four concentrations of Hoagland's solution differed in their response to and interacted with treatment as far as height and diameter growth and total dry matter production in the first growing season were concerned. Varying nutrient intensity did not affect the time of the seasonal peak of height and diameter growth; better growth was maintained subsequent to the seasonal peak at the higher concentrations, however. The proportions of the trees in terms of dry-matter distribution and branching characteristics changed with nutrient concentration.


1995 ◽  
Vol 46 (7) ◽  
pp. 1401 ◽  
Author(s):  
RR Gault ◽  
MB Peoples ◽  
GL Turner ◽  
DM Lilley ◽  
J Brockwell ◽  
...  

Nodulation, N2 fixation (estimated by 15N natural abundance methods) and dry matter production were studied in a lucerne (Medicago sativa) crop managed for hay production at Ginninderra Experiment Station, A.C .T. Measurements were taken in the year of establishment and during two subsequent growing seasons. There were three treatments: (1) no inoculation and no annual fertilizer applied, (2) initial inoculation and superphosphate applied annually, (3) no inoculation, superphosphate applied annually and ammonium sulfate periodically. Before planting and after each growth season, soil was analysed for extractable mineral nitrogen, total nitrogen and the 15N natural abundance of this nitrogen, to the depth explored by lucerne roots. Before planting, no appropriate root-nodule bacteria (Rhizobium meliloti) were detected in the soil and initially plants were nodulated only in the inoculated treatment. Thereafter nodulation increased on the other treatments. Eight months after sowing there were no differences between treatments in numbers of R. meliloti g-l soil or in nodulation. In the third growing season, almost 30 kg ha-1 (dry wt) of nodules were recovered to a depth of 25 cm. These nodules were primarily located on fine, ephemeral roots and many appeared to be renewed after cutting of the lucerne. In the year of establishment, dry matter yields (0% moisture) totalled 3 to 4 t ha-1 in three hay cuts. In succeeding years, total yields were in the range 10 to 13 t ha-1 in four or five cuts per season. Nitrogen removed in the harvested lucerne reached 340 to 410 kg N ha-lyr-l in the second and third years and between 65 and 96% of this N arose from N2 fixation, depending on the method of calculation used. Poorer dry matter production and N2 fixation in treatment 1 in the third growing season was attributed to an insufficient supply of available phosphorus. Fixed N removed in Lucerne hay from treatment 2 totalled at least 640 kg N ha-1 in the three years of the experiment. Also, there were substantial increases in soil nitrogen due to lucerne growth. Although soil compaction made the quantification difficult, at the end of the experiment it was estimated that there was at least an extra 800 kg N ha-1 in the total soil nitrogen under lucerne compared to strips of Phalaris aquatica grown between the lucerne plots. It was concluded that lucerne contributed at least the same amount of fixed nitrogen to the soil as was being removed in the harvested hay.


2006 ◽  
Vol 57 (12) ◽  
pp. 1259 ◽  
Author(s):  
M. Sargeant ◽  
P. Sale ◽  
C. Tang

Salt priming as a tool to establish Distichlis spicata (L.) Greene cv. Yensen-4a (NyPa Forage) plants into saline conditions was investigated in sand culture. Plants were pre-treated with 3 levels of salinity (0, 2, and 4 g NaCl/kg sand) for 36 days and then transplanted into 4 salinity treatments of 0, 2, 4, and 8 g NaCl/kg sand. Soil electrical conductivity (EC), Na and Cl concentrations in the sand, growth initiation, tiller formation, dry matter production, and salt excretion and uptake were measured. Plants pre-treated with 4 g NaCl/kg sand produced 6-fold more dry matter than plants pre-treated with 0 and 2 g NaCl/kg sand when transplanted into sand containing 2 g NaCl/kg. Survival and tiller formation were also higher with plants that had been pre-treated with 4 g NaCl/kg sand compared with plants pre-treated with 0 and 2 g NaCl/kg, when transplanted into 2 and 4 g NaCl/kg sand. The results suggest that salt priming improves establishment of Distichlis spicata when transplanted into low to moderate salinity conditions.


1979 ◽  
Vol 19 (99) ◽  
pp. 437 ◽  
Author(s):  
AC Andrews ◽  
FC Crofts

Four ecotypes of hybrid Bermudagrass (Cynodon dactylon) were compared with common couch (C. dactylon) and kikuyu (Pennisetum clandestinum) at five sites in coastal districts of New South Wales. The sites were Grafton and Coaldale (Lat. 30�S), Mitchells Island (Lat. 32�S) and Richmond and Badgerys Creek (Lat. 34�S). Hybrid Bermudagrass ecotypes 6389 and 692 were established quickly at all sites while ecotypes 71 9 and 632 were satsifactory. Kikuyu was strong at all sites except Grafton but the rate of establishment of common couch was poor. At the frost-free sandy site of Mitchells Island, Bermudagrass ecotypes 719, 692, 6389, and 632 outyielded kikuyu by 75, 65, 65 and 35%, respectively. However, at Grafton and Coaldale, the highest yielding Bermudagrass ecotype, 719, had only 35% higher production than kikuyu. At the frost prone southern sites of Richmond and Badgerys Creek, the annual production of kikuyu was equal to that of ecotypes 719, 6389, 692 and 632. Common couch yields were equal to kikuyu at all sites except at Richmond. At Mitchells Island, the hybrid Bermudagrasses outyielded kikuyu in spring, summer and early autumn but in the late autumn kikuyu had equal and sometimes higher growth rates than the best Bermudagrasses. In winter, the growth of both species was negligible, although kikuyu, unlike the Bermudagrasses, did produce some new shoots at the base of the sward. Data on persistence under grazing were collected from only three of the sites but trends were similar to establishment. Ecotype 6389 had the highest persistence rating of the Bermudagrasses. Kikuyu failed at the poorly drained sandy site of Grafton but remained strong at the other sites. It was concluded that hybrid Bermudagrasses were of potential value for pastures in New South Wales, especially for sites with sandy soils and low frost incidence.


1985 ◽  
Vol 12 (6) ◽  
pp. 641 ◽  
Author(s):  
JS Pate ◽  
NE Casson ◽  
J Rullo ◽  
J Kuo

The growth, longevity, mineral relationships and reproductive biology of 18 species of fire ephemerals were examined in sclerophyllous shrubland, located mainly within the Jurien : Badgingarra region of the Northern Sandplains of the kwongan of SW. Australia. Ten of the species were monocarpic, completing their life cycle within the 6-8 month winter growing season after a summer or autumn fire. The remaining species were polycarpic, commencing reproduction in their second season and surviving and reproducing for a further two to eight seasons (depending on species). Detailed study was made of growth and dry matter allocation in the dioecious, sexually dimorphic, polycarpic species Tersonia brevipes (Gyrostemonaceae). Monocarpic species tended to produce smaller seeds, and exhibited greater seed output per unit biomass and higher harvest indices for dry matter and minerals than polycarpic species. Certain monocarpic species showed great plasticity in final dry weight, e.g. a 2700-fold difference between largest and smallest individuals in a sample of 250 plants of Stipa elegantissima (Poaceae), and a 180-fold range in a similarly sized sample of Macarthuria apetala (Aizoaceae). The fire ephemerals studied generally exhibited faster seedling growth rates, greater concentrations of P and N (but not of Ca, Mg and K) in seedling dry matter, but usually lesser concentrations of P and N (but not of Ca, Mg and K) in seed dry matter than in cohabiting obligate seeder or sprouter species with potential life spans exceeding 15 years. The above-mentioned features of fire ephemerals are suggested to be of special adaptive significance within the context of exploitation of transiently non-limiting habitat resources immediately following fire.


1993 ◽  
Vol 23 (8) ◽  
pp. 1639-1644 ◽  
Author(s):  
Erik Valinger

The effects of thinning and nitrogen fertilization, singly and in combination, on growth of 45-year-old Scots pine (Pinussylvestris L.) trees in northern Sweden were examined for 5 years after treatment. Annual examination of trees determined height growth, diameter growth, crown development, annual biomass increment, aboveground biomass allocation, and needle efficiency in relation to treatments. Nitrogen fertilization increased total dry matter production. The combination of thinning and nitrogen fertilization increased total dry matter production per tree more than the additive effects of thinning and nitrogen fertilization singly. Dry matter production per hectare was increased by nitrogen fertilization. Needle efficiency, i.e., total annual aboveground biomass production per unit of needle mass, was also increased by nitrogen fertilization. The increased aboveground production after nitrogen fertilization resulted from both an increase in biomass of needles and from the increased needle efficiency. The allocation pattern indicated that an increased production of stemwood was a result of a larger biomass of needles. An increase in cone production of the control trees was associated with a decrease in needle efficiency.


CORD ◽  
1997 ◽  
Vol 13 (02) ◽  
pp. 34
Author(s):  
K.V. Kasturi Bai ◽  
V. Rajagopal ◽  
D. Balasimha ◽  
P. Gopalasudaram

The response of local West Coast Tall (WCT) and the two hybrids viz., WCT x Chowghat Orange dwarf (COD) and COD x WCT to moisture availability in terms of water relation, gas exchange and dry matter (DM) production was studied. Discernible differences were noticed between the irrigation treatment (viz., irrigated vs unirrigated) with lower stomatal conductance and transpiration rate in the palms with out irrigation. Irrespective of the cultivar of hybrid leaf water potential was also significantly higher in irrigated palms. Net assimilation rate was lower under uniriigated condition. However genotypic or treatment differences were not significant. Annual DM production also vaned markedly between the irrigation treatments. Treatment differences were significant on the reproductive (RDM) rather then vegetative DM (VDM) production. Under the irrigation treatment the hybrids performed better than the local tall However the percentage reduction in the DM production was relatively less in the local WCT cultivar under unirrigated as compared with irrigated condition. The studies clearly highlighted the beneficial effects of irrigation on DM production and yield in coconut and the adaptability of the local WCT variety under limited water supply than the two hybrids.


2015 ◽  
Vol 40 (2) ◽  
pp. 243-256
Author(s):  
W. Żelawski ◽  
J. Kucharska ◽  
J. Kinelska

Accumulation of dry matter in needles, lignified stems and roots during the second vegetation season was compared with seasonal changes in photosynthesis and respiration activities of the se organs. Whereas growth analysis concerned plants growing at nearly natural course of external conditions, gas exchange determinations were made at constant laboratory conditions. For comparison of dry matter production and photosynthetic ability of a plant new terms „assimilation capacity" and „efficiency of assimilation" were introduced as possible expressions of photosynthetic productivity. Two ecotypes of Scots pine originating from lowland and highland regions of the country exhibited slightly different pattern of the investigated characteristics.


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