Effect of Arachis pintoi groundcover on performance of bananas in northern New South Wales

1994 ◽  
Vol 34 (8) ◽  
pp. 1197 ◽  
Author(s):  
GG Johns

Legume groundcovers have been promoted for controlling soil erosion in hillside banana plantations in northern New South Wales. An experiment was conducted at Alstonville to determine the effect of an Arachis pintoi (Pinto peanut) groundcover on banana productivity. The Arachis groundcover was slow to establish in the first year, but thereafter grew vigorously. While standing dry matter of groundcover was reduced at closer banana plant spacings, it was always more than adequate to control erosion. After 5.5 years many soil chemical parameters had been significantly affected by the presence of groundcover. Organic carbon concentrations to 30 cm depth were 5.6% greater on the groundcover plots (3.94 v. 3.71%), and total nitrogen was 8.5% greater (0.42 v. 0.39%). Other increases were exchangeable potassium 52%, calcium 26%, magnesium 43%, sodium 23%, electrical conductivity 24%, and pH 0.13 units. Banana leaf nutrient concentrations were not affected. Banana plants with groundcover produced 9% fewer bunches than their bare soil counterparts, with 4% fewer fingers per bunch. By the end of the experiment, fingers on the groundcover treatment were 9% lighter; consequently, the weight of marketable fruit (i.e. >120 g/finger) per bunch was reduced by 31% in the final year. The presence of groundcover reduced total fruit production over the whole trial by 16% and marketable fruit by 19%. In the last year of the experiment, total fruit production was reduced by 25%, and marketable fruit production by 40%. Over the whole trial, banana plants with groundcover produced 22% fewer suckers than the bare soil controls, with most of the effect occurring in the first 2 years. Soil temperatures at 20 cm under groundcover were as much as 0.7�C cooler than the controls in October-January, but similar for the rest of the year. This effect possibly contributed to decreased yields. Although the experiment was irrigated, the irrigation was possibly inadequate for the groundcover treatment, and competition for water between the Arachis and banana plants may also have been responsible for part of the yield depression. Rats fed on the buried Arachis seed each winter.

Soil Research ◽  
2009 ◽  
Vol 47 (6) ◽  
pp. 555 ◽  
Author(s):  
Michael G. Jones ◽  
R. Willem Vervoort ◽  
Julie Cattle

Understanding the process by which nutrients and solids enter waterways from pastures in the Great Lakes district, New South Wales, Australia, may assist in maintaining water quality to ensure ongoing environmental and economic sustainability of the region. Rainfall simulations, using a 100-year return storm event, were conducted to determine nutrient and suspended solid concentrations in the runoff of 8 pasture sites in 3 of the catchments in the district. On 5 of the 8 sites, considerable concentrations of N or P were mobilised during the simulated rainfall event, but average nutrient concentrations and total loads across all sites were relatively low and similar to other studies of nutrient runoff from pastures. In addition, low runoff coefficients indicated that runoff is probably not the major pathway for nutrient losses from pasture in this area. Overall, rainfall runoff responses at the sites were similar in the 3 catchments. In contrast, the results suggest that, despite generating more runoff, the sites in the Wang Wauk catchment generated less nutrients in runoff than the sites in the Wallamba and Myall catchments. There was no difference in total suspended solids loads for the sites analysed by catchment. Relationships between soil physical and chemical characteristics and total nutrients loads or cumulative runoff were not strong.


1967 ◽  
Vol 7 (27) ◽  
pp. 372 ◽  
Author(s):  
H Philpotts

In two pot experiments at Narrabri, New South Wales, Poona cowpeas (Vigna sinensis) were sown in a black chernozemic soil at 1, 2, and 4 inches, and at 1 1/2 and 4 inches with and without a straw mulch, to give a range of soil temperatures at the depth of sowing. It was found that the higher the soil temperature at sowing depth the lower was the percentage of plants with nodules and the number of nodules per plant.


1974 ◽  
Vol 14 (66) ◽  
pp. 112 ◽  
Author(s):  
DW Turner ◽  
B Barkus

At Alstonville, New South Wales, leaf position had a greater effect than season on the nutrient concentrations of N, P, K, Ca, Mn, Cu, and Zn in the laminae of Williams bananas growing on a krasnozem soil and sampled over a 4-year period. However, season was more important for Mg. The effect of stage of plant growth was significant but much smaller than the other influences. When sampling for leaf analysis, leaf position and plant age can be standardised, but a major problem in this investigation was unpredictable, significant changes in nutrient composition from one sampling date to another. If these results are true for other soils. the data do not allow critical levels to be applied.


1995 ◽  
Vol 2 (4) ◽  
pp. 398 ◽  
Author(s):  
J. C. Noble ◽  
D. J. Tongway ◽  
M. M. Roper ◽  
W. G. Whitford

The effects of prescribed fires on nutrient pools, soil micro-organisms, and vegetation patch dynamics were studied in three semi-arid mallee shrublands in western New South Wales. Repeated sampling of surface soil strata (0–2 and 2–4 cm) was undertaken at strategic times (immediately before and after the fire, after opening autumn rain, mid-season in the winter, and at the end of the spring) in five microsites (inner, middle and outer mallee litter zones, bare soil, and Triodia hummock). These samples were later analysed for pH, electrical conductivity, organic carbon and available nitrogen. The effect of fire on soil micro-organisms in these microsites was also examined by measuring nitrogenase activity and enumerating soil Acari. Carbon and nitrogen levels were consistently higher in the inner mallee microsites whereas bare soil sites provided the lowest values. Significant microsite x soil depth interactions were recorded in two shrubland sites while highly significant (P < 0.001) depth x sampling time interactions were recorded in three sites. The most sensitive soil parameter with respect to microsite was electrical conductivity, particularly in the surface 0–2 cm stratum. Highest values were again recorded from the inner mallee microsites and the lowest from bare soil sites. Nitrogenase activity was highest in soil samples associated with mallee litter and, where litter was removed by fire, activity decreased markedly except in the bare soil samples where activity was higher in the burnt samples. Soil microarthropod populations also declined notably following fire. Mites from the Prostigmata greatly outnumbered those from other suborders, a total of 12 families (15 genera) being enumerated in control sites compared with three families (three genera) only of Cryptostigmata. Nonetheless the most abundant mites were cryptostigmatids (Aphelacarus spp.) found in unburnt hummocks beneath Triodia plants. The ecological and management implications of these spatial and temporal fluxes in soil chemistry and soil biology are discussed in relation to their effects on landscape processes, particularly water and nutrient redistribution.


1976 ◽  
Vol 16 (79) ◽  
pp. 257 ◽  
Author(s):  
GG Johns ◽  
LR Greenup

At Armidale, New South Wales, ant theft rates of pasture seeds at sites that had been topdressed with 10 kg ha-1 seed immediately before a four day observation period averaged 27 per cent less than on areas where no such application was made. Strong regression relationships were established between theft rates of the various seed types and both air and soil temperatures, but no relationship was found between either relative humidity or soil water availability and theft rate. High theft rates recorded in the first 24 hours after seed placement were not sustained over longer periods of time. A relationship between the decline in theft rate and the quantity of seed available was established. A series of predictions have been made of the proportion of seed likely to remain during fine weather following oversowing in the Armidale environment. These predictions incorporate seed type, time since sowing and prevailing air temperatures. It is predicted that during winter 70 to 80 per cent of bare seed and 90 to 97 per cent of coated seed could remain 30 days after oversowing. During summer the comparable figures are 7 to 30 per cent and 22 to 36 per cent respectively.


1985 ◽  
Vol 12 (3) ◽  
pp. 387 ◽  
Author(s):  
I Parer ◽  
JA Libke

Rabbit warrens in a semiarid environment of New South Wales were concentrated in those areas where impact penetrometer readings indicated friable soil to a depth of at least 75 cm. Isolated warrens in areas with few warrens were found in restricted patches of favourable soil. The absence of warrens from areas with shallow soil was considered to be due to high soil temperatures. The distribution of the rabbit in Australia was examined in relation to deep soil temperatures. It was suggested that the application of bituminous coating on ripped warrens may be a useful technique for the control of rabbits in the arid zone.


2002 ◽  
Vol 42 (7) ◽  
pp. 909 ◽  
Author(s):  
J. D. Croft ◽  
P. J. S. Fleming ◽  
R. van de Ven

Although there have been a number of studies that have examined the effects of rabbits on pasture, the relationship between rabbit density and pasture degradation caused by rabbits has never been quantified. An experiment was conducted at Cowra, New South Wales, from October 1984 to October 1987, to determine the impact various densities of rabbits have on pasture composition, indices of pasture biomass and ground cover. Using plots set stocked with the equivalent of 8 sheep/ha (the district average) and 4 densities of rabbits as treatments, 0,�24, 48 and 72 rabbits/ha, the consequences of rabbit grazing were investigated.Pasture composition changed with season, year and rabbit density. Cumulative effects were also evident. Rabbits severely depleted improved pastures of legumes (subterranean clover particularly), with grass cover increasing proportionate to rabbit density. In the final year of the experiment, the rabbit-free treatment had 31% legumes and 25.2% grasses, whereas the highest rabbit density treatment had 6.2% legumes and 47.4% grasses. Indices of pasture biomass were highest in the zero rabbits/ha treatment and lowest in the 72 rabbits/ha treatment. More bare soil was exposed in the highest rabbit density treatment. Once seasonal and year effects were accounted for, the relationship between rabbit density and percentage damage was positive.


2007 ◽  
Vol 47 (7) ◽  
pp. 869 ◽  
Author(s):  
D. O. Huett ◽  
I. Vimpany

Leaf nutrient analyses are widely used to determine the nutritional status of macadamia orchards. A commercial database was developed from 2186 observations collected from 186 farms across 56 geographical areas spanning New South Wales and Queensland. The data were collected over 10 years, with 1 to 9 sequential annual observations on each farm. An experimental database was also developed where several of the most popular commercial cultivars growing in the Lismore area of New South Wales and the Bundaberg area of Queensland were sampled at monthly intervals over a 2–3 year period. Two canopy sampling heights were used to confirm the effect of shading (irradiance) on leaf nutrient composition. This latter study confirmed that spring was an appropriate time to sample and that irradiated leaves, usually located in an upper canopy position, should be sampled. The most important change to the recommended leaf nutrient standards was the increase in the leaf nitrogen range from 1.3–1.4% to 1.4–1.7% for all cultivars except 344, where we recommend 1.6–2.0%. The study also confirmed that the adequate concentration range for zinc should be much lower than originally recommended. We recommend concentrations of 6–15 mg/kg. Minor changes were made to most other macro- and micronutrients. We also advise caution when interpreting the analyses of some nutrients because concentrations can change over the spring period. The revised leaf nutrient standards were developed from two large and comprehensive databases and reliably represent adequate leaf nutrient concentrations in productive, well-managed macadamia orchards in Australia. A single leaf analysis will not reliably indicate the nutritional status of a macadamia orchard. Additional information is required on trends in leaf and soil analyses over time as well as fertiliser, yield and management history.


1997 ◽  
Vol 37 (1) ◽  
pp. 119 ◽  
Author(s):  
D. O. Huett ◽  
A. P. George ◽  
J. M. Slack ◽  
S. C. Morris

Summary. A leaf nutrient survey was conducted of the low-chill peach cultivars, Flordaprince (October maturing) and Flordagold (mid November–early December maturing) at 3 commercial sites in both northern New South Wales and southern Queensland. Recently mature leaves from the middle third of a current season’s fruiting lateral (spring flush) were sampled at stone hardening and 2-weeks postharvest and of a non-fruiting lateral at maturity of the summer flush (after summer pruning) during the 1992–93 and 1993–94 seasons. At an additional site in New South Wales (Alstonville), leaf nutrient concentrations were also determined on cv. Flordagem (early November maturing) at 2-week intervals during both seasons. Soil (0–30 cm) chemical determinations were conducted at all sites at 2-weeks postharvest Seasonal trends in leaf nutrient composition were associated with a leaf age–maturity effect. As flush leaves matured during spring, and as mature leaves aged after hardening of the summer flush, nitrogen (N) concentration declined and calcium (Ca) concentration increased. Nitrogen and Ca concentrations increased when young leaves produced from the summer flush were sampled. Time of sampling produced the most consistently significant (P<0.05) main effects on leaf nutrient concentration. The 2-week postharvest period was selected as a convenient time to sample—when leaves were of a consistent age and maturity, and the effect of crop load on tree nutrient reserves was still present. Paclobutrazol, which reduces vegetative growth in stonefruit, was applied to all Queensland sites and, as a consequence, mid lateral leaves contained higher (P<0.05) Ca, magnesium (Mg) and chloride (Cl) and lower (P<0.05) N and phosphorus (P) concentrations than leaves from New South Wales sites. State effects can therefore be interpreted as paclobutrazol effects. Cultivar effects (P<0.05) occurred for many leaf nutrients, however, at the 2-week postharvest sampling, concentrations were sufficiently similar to combine as a narrow adequate concentration range for both cultivars. The diagnostic adequate leaf nutrient concentrations were within the range developed for high-chill peaches (Leece et al. 1971) with the exception of lower Ca, lower Mg for New South Wales (both cultivars), lower iron for Flordaprince (both states), higher P for Flordaprince in New South Wales and higher manganese values for Queensland (both cultivars). Regression analyses were conducted between leaf and fruit nutrient concentrations and soil chemical properties. The only consistent result demonstrated that as the soil Ca : Mg ratio increased, leaf Mg concentration decreased exponentially (P<0.001), indicating that the practice of heavy annual agricultural limestone or gypsum applications in the absence of Mg fertiliser, which had been adopted by several growers in the survey, is associated with lower leaf Mg concentrations.


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