Crop and pasture rotations at Coonalpyn, South Australia: effects on soil-borne diseases, soil nitrogen and cereal production

1984 ◽  
Vol 24 (127) ◽  
pp. 555 ◽  
Author(s):  
PM King

A crop rotation experiment was conducted at Coonalpyn, South Australia from 1976 to 1979 on a deep, red duplex soil. The experiment compared the productivity of grain legumes and of volunteer and sown annual pastures, and assessed their effects on the mineral nitrogen supply for subsequent wheat and barley crops, and their capabilities for preventing the root diseases of wheat cereal cyst nematode (Heterodera avenae), bare patch (Rhizoctonia solani) and Haydie (Gaeumannomyces graminis). Satisfactory legume dominance of the annual pastures was achieved only in 1979, while the grain legumes grew well and produced more dry matter than the pastures in each season. Wheat and barley yields averaged (1977- 1979) 2.0 t/ha after volunteer and sown pastures, and 2.8 t/ha after grain legumes, with the greatest response in 1979. In that year, wheat produced 11 kg grain/mm of growing season rainfall after grain legumes, but only 6 kg after pastures. The numbers of lesions on the nodal roots caused by R. solani and on the seminal roots by G. graminis varied with the season but both were less after grain legumes than after pasture. Gaeumannomyces graminis had the greatest effect on grain yield and, with soil nitrate at seeding, explained up to 68% of the variation in yield in 1979.

1991 ◽  
Vol 42 (1) ◽  
pp. 53 ◽  
Author(s):  
JM Fisher ◽  
TW Hancock

Population changes of the cereal cyst nematode (Heterodera avenae Woll.) under various rotational regimes in the field were examined. A density of 5 eggs/g soils caused a loss of about 10% in yield of wheat cv. Bayonet under the experimental conditions. Maximum multiplication rate at low initial densities was about l0x, but this rapidly decreased as initial density increased. Equilibrium levels ranged from 15 eggs/g soil up to 40 eggs/g under different conditions. The resistant wheat, Aus 10894, maintained an equilibrium level of about 1 egg/g soil-a level low enough to avoid damage in a following crop. Annual percentage hatch varied from 70-90% with an average of 85%. Presence or absence of plant species had little effect on per cent hatch. About 7.5% of the nematodes successfully penetrated and became established in the root systems of seedlings, invading both seminal and nodal roots, but only about 0.5% became established in the principal axes of the seminal roots. The implications of these data for various rotational practices are discussed.


1984 ◽  
Vol 35 (6) ◽  
pp. 735 ◽  
Author(s):  
MJ Wood ◽  
AD Robson

Wheat was grown in a soil at five levels of copper (ranging from levels deficient, to those luxurious, for plant growth), in the presence or absence of introduced take-all inoculum (oat kernels colonized by Gaeumannomyces graminis var. tritica). The incidence and severity of take-all were related to the copper supply and hence the copper status of the wheat. Plants grown without applied copper were more severely infected by take-all than were those grown with an adequate or luxurious supply of copper. The number of lesions per gram fresh weight of roots was reduced from 6.5 to 2.4 by increasing the copper supply from that severely deficient, to that adequate for plant growth. In seminal roots, increasing the copper supply from levels severely deficient to those adequate or luxurious for plant growth, decreased the length of proximal lesions (those closest to the seed). By contrast, in nodal roots, a similar increase in copper supply had no effect on the length of proximal lesions, but increased the length of uninfected root between the crown and proximal lesions. In both seminal and nodal roots, copper supply did not affect the intensity of lesions.


1989 ◽  
Vol 40 (3) ◽  
pp. 489 ◽  
Author(s):  
RF Brennan

Wheat was grown in a slightly acid grey sand at six levels of phosphorus and four levels of nitrogen, in the presence and absence of inoculum of Gaeurnannomyces graminis tritici (Ggt) in a glasshouse experiment. Adequate nutrition of N (400 mg/pot) and P (100 mg/pot) for wheat plants was required to overcome take-all of wheat grown for 46 days. Severely N and P deficient plants had 60% of their seminal and nodal roots infected by take-all. As the plants responded to increasing levels of N and P, the percentage of infected nodal and seminal roots steadily declined to 0% and 10% for each root system respectively at luxury levels of P and adequate N. In both the seminal and nodal root system, increasing the N and P supply decreased the length of proximal lesions (closest to seed) and increased the length of the root between the crown and the proximal lesion. The seminal root system was more severely infected with take-all than the nodal root system.


1988 ◽  
Vol 39 (4) ◽  
pp. 541 ◽  
Author(s):  
RF Brennan

Wheat was grown in a slightly acidic grey sand at six levels of phosphorus, in the presence or absence of take-all inoculum in a glasshouse experiment. The incidence and severity of take-all was related to the phosphorus supply and the phosphorus status of wheat.Plants grown without P were more severely infected by take-all than those grown at adequate levels of phosphorus. The percentage of both nodal and seminal roots infected by take-all declined as the level of P was increased. The percentage of seminal roots infected was reduced from 35% to 13.7% by increasing the supply of phosphorus from levels severely deficient to those adequate for plant growth. Infection in nodal roots was reduced from 24% to 2.3% as the P supply increased. In both the seminal and nodal root systems, increasing the P supply decreased the length of proximal lesions (closest to seed) and increased the length of root between the crown and the proximal lesions.


1975 ◽  
Vol 15 (75) ◽  
pp. 556 ◽  
Author(s):  
JH Silsbury

Data are presented for time of flowering, total shoot dry weight and grain yield of White Brunswick pea (Pisum sativum), six introduced peas and one introduction each of Lathyrus sativus and Lathyrus cicera from ten plot experiments conducted in South Australia over the period 1955-1 960.None of the introduced legumes flowered earlier than White Brunswick peas and only one, possibly, has a greater capacity for higher grain yield. L. cicera on the other hand gave 25 per cent greater yield over all sites and seasons with an average of 2.84 tonne ha-1.The ratio between grain yield and total shoot dry weight varied with genotype and between seasons with a genotype. A low ratio was not always associated with low dry matter production.


2004 ◽  
Vol 44 (8) ◽  
pp. 787 ◽  
Author(s):  
I. A. M. Yunusa ◽  
W. D. Bellotti ◽  
A. D. Moore ◽  
M. E. Probert ◽  
J. A. Baldock ◽  
...  

The Agricultural Production Systems Simulator (APSIM) suite of models was used to predict dynamics in water and nitrogen in soil, as well as the growth and yield of sequential crops of wheat and barley in pasture–wheat–barley rotations, between 1995 and 1997 at Roseworthy, South Australia. The NWHEAT model satisfactorily predicted above-ground dry matter, leaf area index and grain yields for both crops in rotations with either grassy (Grass) or medic (Medic) pastures, including the lack of significant response of yield to nitrogen fertiliser applied to wheat at sowing. Simulation data for soil water, from SOILWAT2, was consistent with measured data. Simulation with SOILN2, however, largely underestimated soil nitrogen, due to excessive uptake by the simulated wheat during the season when nitrogen was abundant and water supply readily available. Thus, the soil nitrate had to be reset at sowing for the following barley crop; simulated soil nitrate agreed with the measured data in this season when this nutrient was low. For most variables of crop growth and soil water, the simulated data were mostly within 2 standard errors of the measured means. Prediction of grain protein was underestimated in all cases, including where nitrogen in the shoot was overestimated. This was possibly due to inadequate remobilisation of nitrogen from the straw and roots to the grain by the simulated crop. A satisfactory prediction of dry matter, grain yield and grain weight was obtained for wheat when the models were extended to other trials at Roseworthy (Lower North), Minnipa (Upper Eyre Peninsula) and Wunkar (Murray Mallee), based on limited soil data. Long-term simulations of wheat yields showed that, with early sowing in the Lower North, median wheat yield increased by 50 kg/ha for every kilogram of nitrogen applied at sowing, up to a maximum nitrogen rate of 50 kg/ha. In the drier districts of the Upper Eyre Peninsula and the Murray Mallee, nitrogen fertiliser of no more than 25 kg/ha, applied at sowing, was enough to achieve yield benefits in any given season. At these drier sites, crop failures occurred in 5% (Upper Eyre Peninsula) and 10% (Murray Mallee) of the seasons simulated. Median sowing dates from these simulations were 15 May for the Lower North, 30 May for the Upper Eyre Peninsula and 24 May for Murray Mallee. This suggested that sowing could be conducted at least a week earlier than currently practised in the 3 environments. This study demonstrated the capability of APSIM to predict growth and grain yield of wheat and barley, as well as the associated dynamics of soil water in the main cereal belts of South Australia.


1982 ◽  
Vol 98 (1) ◽  
pp. 7-15 ◽  
Author(s):  
A. J. Barnard ◽  
D. Hornby

SUMMARYMaize was grown for grain or forage on the same site at Woburn for 7 consecutive years. Yields were satisfactory and there were no serious pest or disease problems, provided the small plots were netted until young plants were established. Different rates of nitrogen fertilizer were tested with and without annual applications of a soil sterilant, dazomet. Average yields of grain (85% dry matter) and forage (dry matter) were respectively 4·5 and 8·8 t/ha with 50 kg N/ha and 5·0 and 9·5 t/ha with 100 kg N/ha. Without dazomet there was a further increase with 150 kg N/ha. Weather influenced the response to nitrogen, and the response to a split dressing of the highest rate was variable. Except for plots receiving the split dressing of N in 1973 and 1974 dazomet always increased yields: grain yields were increased on average by 1 t/ha and forage by 1·6 t/ha. Dazomet-treated plots had taller and heavier plants with more stems, leaves and nodal roots, but fewer seminal roots than untreated plots. Dazomet-treated plots also had fewer migratory nematodes and smaller and less varied root myoofloras. Most of these differences were greatest in the young crop and possible reasons for this ‘early boost’ are discussed.


1986 ◽  
Vol 34 (6) ◽  
pp. 709 ◽  
Author(s):  
RH Groves ◽  
PJ Hocking ◽  
A Mcmahon

The heathland form of Banksia marginata Cav. regenerates rarely from seed but commonly by resprout- ing from buds on lateral roots, whereas Banksia ornata F. Muell. regenerates only from seed, usually released after fire. The two species co-occur in heath vegetation on nutrient-poor soils in south-eastern South Australia and western Victoria. Shoots were sampled from stands of B. marginata aged from 1 to 25 years and of B. ornata aged from 1 to 50+ years after fire in the Little Desert National Park, western Victoria. B. marginata, the resprouter, distributed a greater proportion of the total shoot dry matter and content of all nutrients to vegetative growth over its shorter life span than B. ornata, the non-sprouter. About 50% of the total phosphorus in B. ornata shoots at 50+ years was present in cones (including seeds) compared with only about 20% in B. marginata shoots at a comparable stage of senescence (25 years). This difference between the species was also true to a lesser degree for nitrogen. There were considerable differences between other nutrients in their distribution patterns in shoots. Nutrients could be grouped together on the basis of distribution in shoots more satisfactorily than on presumed physio- logical roles. Stems were major sites of nutrient accumulation in both species. The content of a particular nutrient in seeds as a proportion of the content in the living parts of the shoot ranged from 0.03% (Na, Mn) to 2.0% (P) in B. marginata, and from 0.3% (Na) to as high as 31% (P) in B. ornata. Concen- trations of all nutrients except sodium were much higher in seeds than in the woody cones or vegetative organs of both species; seeds of B. ornata were particularly rich in calcium and manganese. We conclude that the different patterns of distribution of biomass and nutrients, especially nitrogen and phosphorus, within shoots of the two species reflect their different regenerative modes after fire. Introduction Phosphorus and, to a lesser extent, nitrogen limit the growth of sclerophyllous shrubs on nutrient-poor soils in southern Australia


Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 201
Author(s):  
Marcal Gusmao ◽  
Delfim Da Costa ◽  
Angelo Da Costa Freitas ◽  
Kadambot H. M. Siddique ◽  
Robert Williams

Growth, development and yield of three-grain legumes (mung bean [F1], soybean [F2] and grass pea [F3]) following rice crop to enhance grain production was studied in a paddy field in the northern Timor-Leste. A split plot design was used with three water treatments (well-watered [W0], water withheld at flowering [W1] and after germination [W2]). Interaction between water treatments and species on dry matter production (p < 0.001) and seed yield (p = 0.005) was observed. In control, the highest seed yield was F1 (1.2 t/ha) followed by F2 (1.1 t/ha) and F3 (0.4 t/ha) respectively. There was a steady reduction in seed yield in F1 from W0 to W2, but almost fifty percent reduction in F2 under W1 and W2 compared to W0. F3 had little difference between water treatments. The W1 and W2 reduced number of filled pods per plant in all species compared to control (W0). Between the species, F3 had the highest filled pods per plant followed by F2 and F3. The W1 and W2 reduced seeds per pod of F1; however, it did not effect F2 and F3. There were interactions between water treatment and species on 100 seeds weight. The heaviest seeds were in F2 in the control plants, but in the F2 drought treatments (W1 and W2) seed weight were less than F3. The lowest seed weight was in F1, but there was no impact of the terminal droughts on its seed weight.


1996 ◽  
Vol 47 (2) ◽  
pp. 199 ◽  
Author(s):  
JR Wilson ◽  
PM Kennedy

Effects of artificial shading to 50% sunlight of nitrogen (N) limited tropical pastures of different grass species on a high (clay loam) and low (granitic loam) fertility soil type were evaluated in a semi-arid. subtropical environment over 3 years. The hypothesis was tested that shade can stimulate shoot growth by providing a modified environment more conducive to organic matter breakdown leading to increased mineralisation and availability of soil N, and the ability of tropical grasses to take advantage of this effect was examined. Unfertilised pastures of green panic (Panicum maximum var. trichoglume), buffel (Cenchrus ciliaris). rhodes (Chloris gayana), and speargrass (Heteropogon contortus) in full sun or shaded by sarlon cloth were sampled on 9 occasions. Additional green panic plots on both soils were irrigated for the first 2 years, and all other plots were dependent on natural rainfall. Shoot and root dry matter and N yield, and soil nitrate and ammonia N, were measured. In one set of green panic plots on each soil, canopy. litter, and surface soil temperatures were monitored continuously, and soil moisture at different depths was measured fortnightly. Shade stimulated shoot dry matter yield over the 3 years by up to 37% in green panic. 22% in rhodes, and 9% in speargrass. Shade decreased buffel yield on the clay soil but had no effect on the granitic soil. Relative increases in yield of shoot N were similar to those for shoot dry matter, except for buffel on the granitic soil where N yield was increased by 39% with no increase in shoot growth. Positive shade responses occurred in all 3 years but were reduced by extreme drought in year 3, particularly on the clay soil. Irrigation gave a greater shade response on the clay but not on the granitic soil. Root mass was lower under shade than in full sun. but there was no long-term trend of progressive decrease. and the change in N yield of roots did not appear to explain the gain in shoot N of the shaded pastures. Nitrogen percentage in the youngest expanded leaf was higher in the shade than the sun leaves only after about 2 to 2 5 months of shading. Surface soil nitrate and ammonia concentrations tended to be higher under shade for most harvests. Shade lowered temperature extremes of surface soil and litter by up to 10-12�C, and improved soil water status. compared with the sun plots. Soil water data were analysed to separate effects on plant water stress and soil microbial activity. The consistent positive response of shoot N yield to shade across grass species. weeds, and soil type. the delay in it becoming evident, and its longevity all support the hypothesis that shade enhances organic matter breakdown and N cycling. Harsh surface temperatures and low soil moisture in open sun pastures appear inimical to high microbial activity. Implications for pasture management are discussed. with the caveat that the outlined benefits of artificial shade may not necessarily arise with tree canopies.


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