scholarly journals Pasture responses to phosphorus and nitrogen fertilisers on dry hill country

1998 ◽  
pp. 135-140 ◽  
Author(s):  
A.G. Gillingham ◽  
M.H. Gray ◽  
D.R. Smith
Keyword(s):  
Soil Moisture ◽  
Large Scale ◽  
Slope Aspect ◽  
Nitrogen Response ◽  
Pasture Production ◽  
Soil P ◽  
Hill Country ◽  
Large Scale Field ◽  
The Difference ◽  
Steep Slopes

In order to evaluate the relative responsiveness of summer-dry hill pasture to phosphate (P) and nitrogen (N) fertilisers, a large scale field trial was established in southern Hawke's Bay in 1995. Pasture growth rates and species, and soil moisture levels were measured on easy and steep slopes of generally north- and south-facing aspects in two pairs of farmlets with either a Low or High soil P status, one of each pair also receiving 30 kg N/ha annually in winter. Soil moisture levels were always higher on south- than on north-facing slopes, the difference being greatest from autumn to spring. However, total annual pasture growth was higher on north aspects because of better winter production, whereas the colder, south aspects produced little pasture at this time. In other seasons, pasture growth was similar on both aspects. Pasture growth was higher on easy than on steep slopes at all times. P responses occurred from spring to autumn especially on south aspects, and on easy north-facing slopes, which showed a large increase in clover growth. N responses were best in winter and autumn especially on steep, north aspects and at Low P conditions. N application depressed clover production, especially in the High P+N fertiliser treatment, where there was no net increase in production compared with the High P treatment. Only tentative conclusions can be made at this time since the pasture is considered to be still in a development phase. However, results suggest that application of P only to south aspects and moist north slopes, and for steep, north-facing slopes to receive N, plus only limited P, will be the most efficient fertiliser policy. Keywords: dry hill country, phosphate response, nitrogen response, pasture production, slope, aspect

scholarly journals Effects of long-term differences in fertiliser history on hill country: seasonal pasture production, legume growth and soil phosphorus status

1995 ◽  
pp. 105-109
Author(s):  
C.G. Roach ◽  
E.K.K. Nemaia ◽  
S.F. Ledgard ◽  
G.J. Brier ◽  
C.D.A. Mclay
Keyword(s):  
Soil Phosphorus ◽  
N Fixation ◽  
Pasture Production ◽  
P Deficiency ◽  
Soil P ◽  
Hill Country ◽  
Legume Production ◽  
Soil Measurements ◽  
Steep Slopes ◽  
Legume Growth

The effects of 10 years of nil or maintenance phosphorus (P) fertiliser (250 kg/ha/yr superphosphate) on pasture production and composition, and on soil P status, were measured in a farmlet trial on hill country near Te Kuiti. Withholding P resulted in 29-35% less annual pasture production and 54-72% less legume (predominantly white clover) production. There was little difference in seasonality of production between the two farmlets. The loss in production in the nil P farmlet was predictable based on the decline in soil Olsen P test to 6-8 ppm and the results from past mowing trials. Additional soil measurements revealed that soil organic P levels were increasing at the site and this will have contributed to the decline in plantavailable P in soil. Re-application of P at 23 kg/ha markedly increased legume growth (by 180-330%) in the nil P farmlet, which was proportionally twice as high on steep slopes as on easy slopes. This response in legume production was most evident in summer at a time when improved feed quality is valuable for finishing lambs. Indeed, legume growth in the P re-application plots exceeded that in the maintenance P farmlet by 23-28%. This reflected reduced plant-available soil N status due to less inputs from N, fixation in the previous 10 years, and thereby increased the competitive advantage of legumes over grasses where P deficiency was diminished by fertiliser re-application. Keywords: fertiliser history, hill country, legume production, pasture production, phosphorus, seasonality, soil phosphorus

scholarly journals Photogrammetric avalanche volume measurements at Vallée de la Sionne, Switzerland

2001 ◽  
Vol 32 ◽  
pp. 141-146 ◽  
Author(s):  
Juauien Vallet ◽  
Urs Gruber ◽  
François Dufour
Keyword(s):  
Large Scale ◽  
Field Experiments ◽  
Test Site ◽  
Deposition Zone ◽  
Before And After ◽  
Large Scale Field ◽  
Volume Measurements ◽  
Snow Distribution ◽  
The Mean ◽  
The Difference

AbstractDuring winter 1999 three large avalanche events were triggered by explosives at SLF’s avalanche test site, Vallée de la Sionne, canton Valais, Switzerland. One important goal of these large-scale field experiments was to measure the release and deposition volumes of avalanches by photogrammetric methods. In this paper, the photogrammetric measurements of all three avalanches are summarized. For one avalanche event it was possible to realize the whole measuring procedure as planned, and to obtain volume measurements before and after the avalanche triggering In the other two avalanche events, the photographs before the triggering of the avalanche failed. Nevertheless the photographs taken after the avalanche provide valuable information on the fracture depth at the fracture line. The mean fracture depth of the largest avalanche was about 2.10 m, varying between 1 and 3.5 m over a width of > 1000 m. The total volume of the deposition of all three avalanche events was about 1300 000 m3. The deposits are distributed over a length of > 1000 m with depths up to 30 m. The difference between the released and deposited volumes proved that avalanches entrain a large amount of snow along the avalanche track. Furthermore, the snow distribution in the deposition zone provides important information about the behaviour of a dense flowing avalanche in the runout zone.

scholarly journals Pasture production gains from strategic winter nitrogen applications on a North Island sheep and beef hill country farm

2008 ◽  
pp. 117-121 ◽  
Author(s):  
M.R. Puha ◽  
W.Mcg King ◽  
V.T. Burggraaf ◽  
A.H.C. Roberts
Keyword(s):  
Key Words ◽  
Animal Production ◽  
Slope Aspect ◽  
Pasture Production ◽  
Hill Country ◽  
Late Autumn ◽  
Major Constraint ◽  
Key Words Nitrogen

Inadequate pasture growth from September to November has been a major constraint on animal production at Limestone Downs, Port Waikato. In an attempt to address this, urea was applied by air in two applications per year (late autumn + winter) at rates up to 250 kg N/ha/year for each of 3 years (2004-2007). Key words: nitrogen, slope, aspect, pasture growth, fertiliser response

Long term effects of withholding phosphate application on North Island hill country: Whatawhata Research Centre

1990 ◽  
pp. 11-16
Author(s):  
A. G.Gillingham S. Richardson ◽  
I.L. Power ◽  
J. Riley
Keyword(s):  
Large Scale ◽  
Soil Depth ◽  
Residual Effects ◽  
Research Centre ◽  
Total Production ◽  
Long Term Effects ◽  
Pasture Production ◽  
Hill Country ◽  
Olsen P ◽  
Fertiliser Application

From June 1984 to May 1988 a large-scale grazing trial at Whatawhata Research Centre evaluated the effects of a halt to previous superphosphate fertiliser application on hill country production. Over the 4-years pasture production, pasture species composition, stock grazing days or Olsen P soil fertility status were little affected as a result of halting topdressing. Pasture production declined most on 'easy' ( lo-20° slope) slopes after a halt to fertiliser application. The decline was greatest (lo- 13 %) where previous rates of fertiliser had been high. Total production on 'steep' (30~40° slope) slopes did not decline significantly. However, at soil test (Olsen P) levels of less than 10 the pasture moss and dead matter content increased, indicating a deterioration in pasture quality. Legume content did not decline. Within the range of normal topdressing rates to hill country (O-30 kg P/ha/yr) Olsen P tests did not reflect topdressing differences or any effects of a halt to fertiliser application. At higher topdressing rates (50-100 kg Plhalyr) the effect of continued or discontinued topdressing was reflected predominantly in the O-3 cm soil depth. A halt to previous topdressing significantly reduced available grazing over the final 3 years. This decline reflected the decline in measured pasture production. Keywords Phosphate, fertiliser, hill country, residual effects

scholarly journals Variability of the Indian Monsoon in the ECHAM3 Model: Sensitivity to Sea Surface Temperature, Soil Moisture, and the Stratospheric Quasi-Biennial Oscillation

1998 ◽  
Vol 11 (8) ◽  
pp. 1837-1858 ◽  
Author(s):  
K. Arpe ◽  
L. Dümenil ◽  
M. A. Giorgetta
Keyword(s):  
Soil Moisture ◽  
Arabian Sea ◽  
Large Scale ◽  
Monsoon Season ◽  
Sea Surface ◽  
Northern Indian Ocean ◽  
Quasi Biennial Oscillation ◽  
The Difference ◽  
Biennial Oscillation

Abstract The variability of the monsoon is investigated using a set of 90-day forecasts [MONEG (Tropical Ocean Global Atmosphere Monsoon Numerical Experimentation Group) experiments] and a set of AMIP-type (Atmospheric Model Intercomparison Project) long-term simulations of the atmospheric circulation with the ECHAM3 model. The large-scale aspects of the summer monsoon circulation as represented by differences of dynamical quantities between the two extreme years 1987 and 1988 were reproduced well by the model in both kinds of experiments forced with observed sea surface temperature (SST). At the regional scale the difference of precipitation over India during summer 1987 and 1988 was well reproduced by the model in the 90-day forecasts using interannually varying SSTs; however, similarly good results were achieved in forecasts using climatological SSTs. The long-term simulations forced with interannually varying SST at the lower boundary of the atmosphere over a period of 14 years, on the other hand, only partly reproduce the observed differences of precipitation over India between 1987 and 1988. For the ensemble mean of five simulations averaged from June to September and for the whole of India an increase from 1987 to 1988 is simulated by the model as observed but with smaller values. The difference in observed precipitation between 1987 and 1988 is of opposite sign for May to that for September. The simulations and observations agree in the manifestation of this sense of opposing variability within a monsoon season for these two years and also for other years. The simulations and observations differ most during July. The paper concentrates on the question why the interannual variability in the long-term simulations on one hand and the 90-day forecasts and in the observations of precipitation on the other hand differ so strongly during the peak of the monsoon in July. Large-scale dynamics over India are mainly forced by the anomalies of Pacific SST. For the variability of precipitation over India other forcings than the Pacific SST are important as well. Due to enhanced evaporation, warmer SSTs over the northern Indian Ocean lead to increased precipitation over India. Changes in the SST there within the range of uncertainty (0.5 K) can lead to clear impacts. As a further boundary forcing, the impact of soil moisture is investigated. The use of realistic soil moisture differences between 1987 and 1988 in the MONEG forecasts resulted in improved skill of precipitation forecasts over India. Also the two individual AMIP simulations with realistic precipitation differences over India had more realistic soil moisture differences over east Asia in the beginning of the monsoon season between the two years than those experiments that failed to produce the correct precipitation differences. The years 1987 and 1988 were quite different with respect to the phase of the stratospheric quasi-biennial oscillation (QBO). As atmospheric circulation models cannot yet reproduce stratospheric QBOs realistically, their impact was tested by nudging observed QBOs into AMIP simulations for July 1987 and 1988. Seven out of eight experiments showed an impact toward a more realistic simulation of precipitation over India; however, during the west phase of the QBO (1987) impacts are very small. None of these forcings gave a dominant effect. If this finding is confirmed by further experimentation, improvements of practical long-range forecasts may be very difficult as two of these quantities are hardly known with the required accuracy (northern Indian Ocean SSTs and the Eurasian soil moisture) and because models are not yet able to simulate the stratospheric QBO realistically. This study confirms that El Niño has two direct effects: it reduces the precipitation over India and reduces the surface winds over the Arabian Sea. Due to the latter, the SST of the Arabian Sea can increase as there is less mixing and upwelling in the ocean. Here it is suggested that because of this increased SST there would be more precipitation over India, thus counteracting the expected decrease from the direct El Niño effect. Sensitivity experiments were carried out with the ECHAM3 model to substantiate this hypothesis. The results may be model-dependent and model deficiencies might influence sensitivities from boundary forcings adversely. Therefore observational data have been investigated as far as possible to seek independent confirmation of the findings obtained through the model simulations.

scholarly journals A field experiment shows that subtle linguistic cues might not affect voter behavior

2016 ◽  
Vol 113 (26) ◽  
pp. 7112-7117 ◽  
Author(s):  
Alan S. Gerber ◽  
Gregory A. Huber ◽  
Daniel R. Biggers ◽  
David J. Hendry
Keyword(s):  
Field Experiment ◽  
Voter Turnout ◽  
Large Scale ◽  
Point Estimate ◽  
Significant Difference ◽  
Linguistic Cues ◽  
Scale Field ◽  
Recent Developments ◽  
Large Scale Field ◽  
The Difference

One of the most important recent developments in social psychology is the discovery of minor interventions that have large and enduring effects on behavior. A leading example of this class of results is in the work by Bryan et al. [Bryan CJ, Walton GM, Rogers T, Dweck CS (2011) Proc Natl Acad Sci USA 108(31):12653–12656], which shows that administering a set of survey items worded so that subjects think of themselves as voters (noun treatment) rather than as voting (verb treatment) substantially increases political participation (voter turnout) among subjects. We revisit these experiments by replicating and extending their research design in a large-scale field experiment. In contrast to the 11 to 14% point greater turnout among those exposed to the noun rather than the verb treatment reported in the work by Bryan et al., we find no statistically significant difference in turnout between the noun and verb treatments (the point estimate of the difference is approximately zero). Furthermore, when we benchmark these treatments against a standard get out the vote message, we estimate that both are less effective at increasing turnout than a much shorter basic mobilization message. In our conclusion, we detail how our study differs from the work by Bryan et al. and discuss how our results might be interpreted.

scholarly journals Precise aerial fertiliser application on hill country

1999 ◽  
pp. 221-226
Author(s):  
A.G. Gillingham ◽  
J. Maber ◽  
J. Morton ◽  
M. Tuohy
Keyword(s):  
Application Rate ◽  
Economic Returns ◽  
Related Factors ◽  
Pasture Production ◽  
Economic Return ◽  
Soil P ◽  
Topographic Complexity ◽  
Hill Country ◽  
Olsen P ◽  
Fertiliser Application

The fertiliser requirements of hill country vary with soil type, slope and aspect-related factors which govern pasture production potential and species composition. In most situations, the topographic complexity is such that only very broad differentiation in land units can be made when aerially applying fertiliser. The traditional method of aerial topdressing is for superphosphate to be flown on at a common rate over large blocks of complex topography by fixed-wing aircraft. Advances in geographical positioning system (GPS) and aircraft technology now allow aircraft to fly accurately defined track spacing and so achieve optimum uniformity of fertiliser spread. The same technology could be used to vary fertiliser application rate along a flight path according to predetermined recommendations and through links to a farm geographic information system (GIS) map. This approach could also be used to apply different fertiliser types. In a desktop study the effects of differential, compared with uniform, fertiliser application policies, on animal productivity and economic returns were examined for three contrasting hill farm situations using a combination of trial results and the AgResearch PKS Lime Programme. Results showed that for a farm with a low soil P status (Olsen P =9), that stocking rate could be increased by 0.5 su/ha, and the economic return by 7.5%, by differential, rather than uniform fertiliser application. In a similar but higher soil P status farm (Olsen P = 15), the increase was 0.9 su/ ha and 10.1% respectively. In a summer-dry situation where nitrogen fertiliser could be substituted for some P fertiliser, a differential policy designed to optimise production gave a 2.1 su/ha and 43% net margin increase, compared with the uniform application of a typical rate of maintenance P fertiliser only. The results from the desktop study are discussed in relation to the practical aspects of developing differential fertiliser application methods. This will relate to extra fertiliser application cost, and the definition of practical sized land units and fertiliser forms, which will all have some effect on the net economics of a differential application policy. Despite these unknowns, the technology would appear to offer real gains to the hill country farmer. Keywords: economic return, fertiliser application, GIS, GPS, hill country, phosphate

Long term effects of withholding phosphate application on North Island hill country: Economics

1990 ◽  
pp. 29-33
Author(s):  
D.A. Clark ◽  
S.F. Ledgard ◽  
M.G. Lambert ◽  
M.B. O'Connor ◽  
A.G. Gillingham
Keyword(s):  
Cash Flows ◽  
Cost Ratio ◽  
Long Term Effects ◽  
Pasture Production ◽  
Soil P ◽  
Hill Country ◽  
Fertiliser Application ◽  
Positive Cash Flow ◽  
Sustainable Productivity

Results from fertiliser cessation experiments at Ballantrae, Te Kuiti and Whatawhata, on yellow-brown earths, were used to evaluate the fertiliser cessation compared to continued application on hill country breeding ewe systems. At Balhmtrae, on farmlets previously receiving 125 kg superphosphate/ha/yr, continued fertiliser application generated a positive cash flow after 8 years. On farmIets previously receiving rates of 200-375 kg superphosphate/ha/yr positive cash flows were generated by continued fertiliser application after 4, 5 and 6 years at Te Kuiti, Whatawhata and Ballantrae respectively. Fertiliser cessation is a sound strategy to survive periods of low product price:fertiIiser cost ratio. However, it will decrease sustainable productivity and hence farm resale value. Fertiliser recommendations cannot remain constant over time but must consider: animal enterprise, product and fertiliser price, soil P status, and level of pasture utilisation. Keywords fertiliser cessation, superphosphate, Olsen P, economics, hill country, pasture production

RATIONALISING TOPDRESSING OF HILL COUNTRY

1984 ◽  
pp. 92-97
Author(s):  
A.G. Gillingham ◽  
S.C. Richardson ◽  
J. Riley
Keyword(s):  
Production Efficiency ◽  
Relative Yield ◽  
Maximum Growth ◽  
Pasture Production ◽  
Hill Country ◽  
Olsen P ◽  
Phosphate Fertiliser ◽  
Soil Complex ◽  
Relative Production ◽  
Steep Slopes

Measuremgnts of Pasture production were made on both Easy (1 O-20' slope) and Steep (30-40 slope) strata of a yellow brown earth-brown granular loam hill soil complex of medium P retention status. Results showed that whereas maximum growth required 50 kg P/ha/year on Easy slopes (14,900 kg DM/ha) only 30 kg P/ha/year were needed on Steep slopes (7700 kg DM/ha). Efficiency of production IEP) in kg DM/kg P from Easy and Steep slopes was similar at the same relative production level but much higher from Easy slopes at any one fertiliser rate. There was a poor relationship between soil Olsen P status and relative yield. However maximum production was obtained with mean Olsen P levels (O-7 cm depth) of 15, on Easy Slopes, and 10 on the Steep slopes. A procedure is described to assist in setting fertiliser rates for topdressing hill country. Keywords: hill country, phosphate fertiliser, pasture production, efficiency of production

scholarly journals Sex-Related Differences in Growth, Herbivory, and Defense of Two Salix Species

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 450 ◽  
Author(s):  
Guo Yang ◽  
Qiang Xu ◽  
Wei Li ◽  
Jiahao Ling ◽  
Xiaoping Li ◽  
...  
Keyword(s):  
Resource Allocation ◽  
Sex Ratio ◽  
Large Scale ◽  
Growth Traits ◽  
Insect Herbivory ◽  
Great Influence ◽  
Large Scale Field ◽  
Female Bias ◽  
The Difference ◽  
Evolution Of Dioecy

Sex-related differences in sex ratio, growth, and herbivory are widely documented in many dioecious plants. The common pattern is for males to grow faster than females and to be less well-defended against herbivores, but Salix is an exception. To study sex-related differences in the patterns of resource allocation for growth and defense in willows, we conducted a large-scale field experiment to investigate the flowering sex ratio, mortality, growth traits, insect herbivory and content of defensive substances in three Salix populations comprising two species. Results demonstrate that the two Salix suchowensis Cheng populations have a female bias in the sex ratio, whereas no bias is found in the S. triandra L. population. Male individuals in the S. suchowensis populations have significantly higher mortality rates than females. However, the mortality rate of S. triandra population has no gender difference. This finding may be one of the explanations for the difference in sex ratio between the two species. The females are larger in height, ground diameter, and biomass, and have a higher nutritional quality (N concentration) than males in both species. Nevertheless, slow-growing males have a higher concentration of the defense chemical (total phenol) and lower degrees of insect herbivory than females. Additionally, biomass is positively correlated with herbivory and negatively correlated with defense in the two willow species. It is concluded that the degrees of herbivory would have a great influence on resource allocation for growth and defense. Meanwhile, it also provides important implications for understanding the evolution of dioecy.

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