Optimising maize plant population and irrigation strategies on the Darling Downs using the APSIM crop simulation model

2008 ◽  
Vol 48 (3) ◽  
pp. 313 ◽  
Author(s):  
A. S. Peake ◽  
M. J. Robertson ◽  
R. J. Bidstrup
Keyword(s):  
Simulation Model ◽  
Plant Population ◽  
Soil Types ◽  
Crop Failure ◽  
Higher Plant ◽  
Plant Populations ◽  
Crop Simulation ◽  
Gross Margins ◽  
Irrigation Volume

Optimum plant population and irrigation strategies for maize grown in the Dalby district of the Darling Downs in Queensland, Australia, were investigated using the APSIM crop simulation model. After testing the model against three seasons of experimental data, simulation experiments using different irrigation strategies were conducted across a range of plant populations ranging from 20 000 to 80 000 plants/ha, on two soil types with plant available water capacities (PAWC) of 146 mm and 220 mm. All soil type × plant population × irrigation strategy scenarios were simulated using the historical climate record for Dalby from 1889 to 2004, in order to obtain long-term average yield and gross margins (LGM) for each scenario. Soil water was reset to two-thirds of PAWC at sowing in each year. Plant populations required to achieve maximum LGMs ranged from 50 000 to 80 000 plants/ha across the range of scenarios, and were higher than currently recommended by district agronomists for partially irrigated maize. The use of higher plant populations increased season-to-season variability in grain yield and gross margins and may not be a suitable strategy for growers who do not want to increase their risk of crop failure. Partially irrigated maize achieved substantially higher gross margins in years where a positive Southern Oscillation Index phase was recorded in August, and the use of higher plant populations in such years also increased long-term profitability, but also increased the risk of crop failure. Economic gains were achieved by varying the timing and amount of irrigation within a limited available irrigation volume, with a single 100 mm irrigation giving greater LGMs than two 50 mm irrigation events on both soil types, when the irrigation events were scheduled to fill a soil water deficit equal to the effective irrigation volume. However, under full irrigation the use of smaller irrigation volumes increased LGMs on the 146 mm PAWC soil, demonstrating the importance of timely irrigation scheduling on low PAWC soils.

Analysis of high yielding maize production - a study based on a commercial crop

2008 ◽  
Vol 48 (3) ◽  
pp. 296 ◽  
Author(s):  
C. J. Birch ◽  
G. McLean ◽  
A. Sawers
Keyword(s):  
Retrospective Analysis ◽  
Environmental Conditions ◽  
Sowing Date ◽  
Plant Population ◽  
Higher Plant ◽  
Maize Crop ◽  
Wide Range ◽  
Commercial Crop ◽  
Reduced Temperature

This paper reports on the use of APSIM – Maize for retrospective analysis of performance of a high input, high yielding maize crop and analysis of predicted performance of maize grown with high inputs over the long-term (>100 years) for specified scenarios of environmental conditions (temperature and radiation) and agronomic inputs (sowing date, plant population, nitrogen fertiliser and irrigation) at Boort, Victoria, Australia. It uses a high yielding (17 400 kg/ha dry grain, 20 500 kg/ha at 15% water) commercial crop grown in 2004–05 as the basis of the study. Yield for the agronomic and environmental conditions of 2004–05 was predicted accurately, giving confidence that the model could be used for the detailed analyses undertaken. The analysis showed that the yield achieved was close to that possible with the conditions and agronomic inputs of 2004–05. Sowing dates during 21 September to 26 October had little effect on predicted yield, except when combined with reduced temperature. Single year and long-term analyses concluded that a higher plant population (11 plants/m2) is needed to optimise yield, but that slightly lower N and irrigation inputs are appropriate for the plant population used commercially (8.4 plants/m2). Also, compared with changes in agronomic inputs increases in temperature and/or radiation had relatively minor effects, except that reduced temperature reduces predicted yield substantially. This study provides an approach for the use of models for both retrospective analysis of crop performance and assessment of long-term variability of crop yield under a wide range of agronomic and environmental conditions.

Yield-density relationships and optimum plant populations in two cultivars of solid-seeded dry bean (Phaseolus vulgaris L.) grown in Saskatchewan

2002 ◽  
Vol 82 (3) ◽  
pp. 521-529 ◽  
Author(s):  
Steven J. Shirtliffe ◽  
Adrian M. Johnston
Keyword(s):  
Seed Weight ◽  
Plant Density ◽  
Maximum Yield ◽  
Plant Population ◽  
Seeding Density ◽  
Seeding Rate ◽  
Higher Plant ◽  
Plant Populations ◽  
Dry Bean ◽  
Density Relationship

There is relatively little agronomic information on solid-seeded production of dry bean in western Canada. Recommended seeding density for dry bean can depend on the growth habit of the plant, the yield–density relationship, percent emergence, seed cost and environment. The objective of this study was to determine the yield–density relationships in two determinate bush type cultivars of dry bean and the optimum plant population under solid-seeded production in Saskatchewan. CDC Camino, a late-season pinto bean and CDC Expresso, a medium-season-length black bean were the cultivars evaluated. In most sites, the yield-density relationship of the cultivars was asymptotic and an optimum plant density for maximum yield could not be determined. Camino generally required a lower plant population to reach a given yield than Expresso. Increasing plant population did not affect 1000-seed weight. Higher seeding rate did result in a greater number of seeds produced m-2, with Expresso having a greater increase in seed produced m-2 compared with Camino. Expresso was required to be at higher plant densities than Camino to maximize economic returns. This reflects the differences between cultivars in yield-density relationship and seed cost, as Camino has a heavier 1000-seed weight than Expresso. Saskatchewan bean growers wishing to maximize profit should target plant populations for Expresso and Camino of approximately 50 and 25 plants m-2, respectively. Key words: Saskatchewan, yield components, non-linear regression, seeding rate, narrow rows, solid-seeded

scholarly journals Transplanting as a means to enhance crop security of fodder beet

2016 ◽  
Author(s):  
EN Khaembah ◽  
WR Nelson
Keyword(s):  
Canopy Cover ◽  
Significant Loss ◽  
Plant Population ◽  
Weed Competition ◽  
Crop Failure ◽  
Plant Populations ◽  
Fodder Beet ◽  
Crop Establishment ◽  
Target Plant ◽  
Early Establishment

AbstractFodder beet has become a popular winter feed for all stock classes in New Zealand. However, poor crop establishment frequently leads to either significant loss in yield, through below-target plant populations, weed competition, or crop failure. This study demonstrates that establishing the crop from transplants, common in the vegetable industry, is one way to achieve a uniform plant population and reduce weed competition through early establishment of canopy cover. The most significant effect of transplant establishment is that the target plant population is readily achieved.

scholarly journals PLANT SPACING AND NITROGEN INFLUENCE ON STRAWBERRY GROWTH AND FRUITING

HortScience ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 399c-399
Author(s):  
Elden J. Stang ◽  
Gavin G. Weis
Keyword(s):  
Plant Population ◽  
Fruit Yield ◽  
Growth And Yield ◽  
Higher Plant ◽  
Plant Populations ◽  
Available N ◽  
Berry Size ◽  
Plant Densities ◽  
Nitrogen Treatments ◽  
Population Effects

`Raritan' and `Guardian' strawberry were grown in the matted row system with controlled plant densities of 1, 2, 3, 4 or 5 plants/0.09m2 for comparison to a non-thinned matted row averaging 9 plants/0.09m2. Nitrogen treatments were superimposed on plant spacings at 3 week intervals in preharvest and postharvest applications. Total seasonal available N was 0, 36, 54 and 76 kg/ha. Fruit yield per plant decreased as plant population increased. Berry size declined with increased plant population but number of fruit per plant was not influenced. For both cultivars, plant populations of 4 to 5 plants/0.09m2 resulted in maximum fruit yield. Number of branch crowns for all treatments was 2.5-3.5/plant in the second growing season. Branch crown numbers were reduced with higher plant populations. N effects were independent of plant population effects and did not compensate for lower yields at low plant populations in more or larger berries. Optimum water management may be more important than N fertilizer in determing strawberry plant growth and yield.

scholarly journals Effects of plant population and nitrogen fertilizer on yield and efficiency of maize-bean intercropping

2003 ◽  
Vol 38 (11) ◽  
pp. 1257-1264 ◽  
Author(s):  
Luiz Balbino Morgado ◽  
Robert William Willey
Keyword(s):  
Nitrogen Fertilizer ◽  
Fertilizer Application ◽  
Plant Population ◽  
Bean Plant ◽  
Dry Matter Accumulation ◽  
Higher Plant ◽  
Plant Populations ◽  
Nitrogen Levels ◽  
Sole Cropping ◽  
Basic Parameters

Nitrogen supply and plant population are basic parameters for cereal-legume intercropping. In order to study plant population and nitrogen fertilizer effects on yield and yield efficiency of maize-bean intercropping, a field experiment was established. Three bean plant populations and three nitrogen levels were used. Maize dry matter accumulation decreased with increases in bean plant population. Competitive effect of intercrop beans on maize yields was high at higher plant populations, being decreased by nitrogen fertilizer; application of 50 kg ha-1 N was very efficient in increasing maize cob yield. Intercropping significantly decreased harvest index of beans in all plant population and nitrogen fertilizer situations. The efficiency of intercropping, compared to sole cropping, was evidenced by the values obtained for Land Equivalent Ratio (LER) for biomass, cob and pod yields that increased with increases in bean plant populations and nitrogen fertilizer levels.

Lucerne improves some sustainability indicators but may decrease profitability of cropping rotations on the Jimbour Plain

2005 ◽  
Vol 45 (6) ◽  
pp. 651 ◽  
Author(s):  
R. B. Murray-Prior ◽  
J. Whish ◽  
P. Carberry ◽  
N. Dalgleish
Keyword(s):  
Standard Deviation ◽  
Simulation Model ◽  
Stochastic Dominance ◽  
Sustainability Indicators ◽  
Crop Simulation Model ◽  
Crop Simulation ◽  
Efficiency Measures ◽  
Long Run ◽  
Gross Margins ◽  
Group Rotations

Long-run rotational gross margins were calculated with yields derived from biophysical simulations in a crop simulation model over a period of 100 years and prices simulated in @Risk based on subjective triangular price distributions elicited from the Jimbour Plain farmer group. Rotations included chickpeas, cotton, lucerne, sorghum, wheat and different lengths of fallow. The aim was to assess the profitability of rotations with and without lucerne. Output presented to the farmers included mean annual gross margins and distributions of gross margins with box and whisker plots found to be suitable. Mean–standard deviation and first- and second-degree stochastic dominance efficiency measures were also calculated. The paper outlines a method for combining biophysical and price simulations that can be understood by farmers. Including lucerne in the rotations improved some sustainability indicators but reduced profitability.

Plant population, shading and thinning studies in wheat

1971 ◽  
Vol 77 (3) ◽  
pp. 453-461 ◽  
Author(s):  
R. W. Willey ◽  
R. Holliday
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Unit Area ◽  
Grain Filling ◽  
Plant Population ◽  
Growth Stages ◽  
Response Curves ◽  
Higher Plant ◽  
Plant Populations ◽  
Ear Development

SUMMARYThree wheat experiments are described in which a range of plant populations were shaded during different periods of development; in two of the experiments plant thinning was also carried out at a number of growth stages. Shading during the period of ear development caused an appreciable decrease in grain yield by decreasing the number of grains per ear. Shading during the grain filling period also reduced grain yield, this being brought about by decreased grain size. Thus in contrast to the barley experiments reported earlier (Willey & Holhday, 1971), these particular results gave no indication of a potential surplus of carbohydrate for grain filling and an associated limited ear capacity. However, when plant thinning was carried out at anthesis to make more carbohydrate available for grain filling in the remaining ears, grain yield per ear did not increase. It is argued, therefore, that grain yield probably was determined at least partly by a limited ear capacity. Plant thinning at earlier stages showed how the development of competition during the ear development period progressively reduced the potential capacity of the ear; the greater competition of higher plant populations accelerated this reduction in ear potential.From an examination of the effects of plant population, it is suggested that the number of grains per ear is the component having greatest influence on the decline in grain yield at above-optimum populations. The possible importance of the number of grains per unit area as an indicator of ear capacity on an area basis, and as a determinant of grain yield per unit area, is emphasized. A close relationship between grain yield per unit area and number of grains per unit area is illustrated for a number of plant-population response curves, and it is suggested that the decrease in grain yield at high populations is probably determined by a decrease in the number of grains per unit area. Evidence is presented to substantiate the idea put forward in the barley paper that this decrease in the number of grains per unit area may be attributable more to a lower production of total dry matter by the high populations during the later stages of ear development, than to an unfavourable partitioning of such dry matter between the ear and the rest of the plant.

Agronomic Factors Influencing Yield and Quality of Groundnuts in the Sudan Gezira

1967 ◽  
Vol 3 (1) ◽  
pp. 41-53 ◽  
Author(s):  
W. M. Tahir ◽  
M. S. Misovic
Keyword(s):  
Oil Content ◽  
Clay Soil ◽  
Plant Population ◽  
Higher Plant ◽  
Plant Populations ◽  
Kernel Weights ◽  
Yield And Quality ◽  
Heavy Clay ◽  
Sudan Gezira

SummaryAn early upright-bunch variety of groundnut, Barberton, and a medium-late spreading-bunch variety, Ashford, were compared at 7·5, 15·0 and 30·0 cm. intra-row spacings planted at one and two kernels per hill on 60 cm. ridges in the irrigated heavy clay soil of the Sudan Gezira in 1963 and 1964. Barberton was harvested on days 95, 110 and 125, and Ashford on days 125, 140 and 155 after planting in July–August. Ashford outyielded Barberton at the lower densities, and the best pod yields were obtained on day 125 harvest at a population of 55,000–60,000 plants per acre. A higher plant population depressed the yield of Ashford while the increased pod yield of Barberton was not significant. Field germination of kernels increased more in Barberton with delay in harvest and with decrease in plant population than in Ashford. Mean pod and kernel weights and shelling out-turn of Barberton increased with delay in harvest. Barberton gave higher oil content and shelling out-turn, and lower proportion of pods with single kernels than Ashford. The highest population of Barberton gave the best oil content in early harvests. In general, the arrangement of plants within rows at similar populations had only small effects except on the quality of nuts, which was improved by planting single kernels at close spacing (7·5 cm.) with the variety Barberton and two kernels at wide spacing (15·0 cm.) with Ashford, at optimum plant populations.

Plant Population, Rainfall and Sorghum Production in Botswana. II. Development of Farmer Recommendations

1987 ◽  
Vol 23 (3) ◽  
pp. 349-356
Author(s):  
M. J. Jones
Keyword(s):  
Rainfall Amount ◽  
Plant Population ◽  
Crop Failure ◽  
Sorghum Variety ◽  
Regional Population ◽  
Sorghum Production ◽  
One Year

SUMMARYRegional population recommendations for sorghum production in Botswana were calculated by applying long-term meteorological records to an experimentally developed model linking sorghum yield to plant population and rainfall. The basic recommendation at any place was taken to be that population maximizing local long-term yield means while keeping the risk of crop failure to one year in ten or less. Values ranged from 25 000 to nearly 70 000 plants ha−1, according to rainfall amount and reliability. The modifications of these basic recommendations necessary to allow for differences in standards of husbandry and for sorghum variety are discussed.

scholarly journals Light interception and utilization of four grain legumes sown at different plant populations and depths

2004 ◽  
Vol 142 (3) ◽  
pp. 297-308 ◽  
Author(s):  
S. AYAZ ◽  
B. A. McKENZIE ◽  
D. L. McNEIL ◽  
G. D. HILL
Keyword(s):  
Seed Yield ◽  
Grain Legumes ◽  
Plant Population ◽  
Radiation Absorption ◽  
Grain Legume ◽  
Legume Species ◽  
Higher Plant ◽  
Plant Populations ◽  
Area Index ◽  
Canopy Development

Canopy development, radiation absorption and its utilization for yield was studied in four grain legume species Cicer arietinum, Lens culinaris, Lupinus angustifolius and Pisum sativum. The grain legumes were grown at different plant populations and sowing depths over two seasons in Canterbury, New Zealand. The green area index (GAI), intercepted radiation, radiation use efficiency (RUE) and total intercepted photosynthetically active radiation (PAR) increased significantly (P<0·001) with increased plant population. Narrow-leafed lupin produced the highest maximum biomass (878 and 972 g/m2, averaged over all populations during 1998/99 and 1999/2000, respectively) and intercepted more radiation (600 and 714 MJ/m2, averaged over all populations during 1998/99 and 1999/2000, respectively) than the other three legumes. In all four species, in both trials, the highest plant populations reached their peak GAI about 7–10 days earlier than legumes sown at low populations. Cumulative intercepted PAR was strongly associated with seed yield and crop harvest index (CHI).The RUE increased (from 1·10 to 1·46 and from 1·04 to 1·34 g/MJ during 1998/99 and 1999/2000, respectively) as plant population increased and was highest in the highest yielding species (e.g. 146 and 1·36 g/MJ for narrow-leafed lupin in both experiments). The larger leaf canopies produced at the higher plant populations reduced the extinction coefficient (k).The results suggest that in the subhumid temperate environment of Canterbury, grain legume species should be selected for the development of a large GAI. This should maximize PAR interception, DM production and, consequently, seed yield.

Sign in / Sign up

Export Citation Format

Share Document