scholarly journals Fatores determinantes para a construção do potencial produtivo da soja em terras baixas

2020 ◽  
Vol 42 ◽  
pp. 27
Author(s):  
Alex Alan Bredow ◽  
Alicia Baumhardt Dorneles ◽  
Mara Grohs ◽  
Rodrigo De Moura Silveira ◽  
Giovane Rodrigo Friedrich Neu ◽  
...  

The soybean is an alternative of diversification and financial return to the rice farmer. However, it presents difficulties of cultivation and low yield due to the physical characteristics of the soil. In this scenario, the objective of this work was to verify the influence of soil scarification, the genetic material used and the sowing date. Three soybean cultivars, with yield potential classified as “medium”, “high” and “very high”, were sown in a scarified and non-scarified area, in the dates november 7th and december 10th, year of 2018. The scarification opperation occurred on october 1st. Initial establishment varied according to cultivar, soil mechanism and sowing date. Soil scarification effect was verified up to 100 days after the operation. Within the construction of the yield potential, scarification accounted for 14.4 %, sowing date 12.5 % and genetic material 73.1 % of crop grain yield, in the “high” and “very high” potential materials.

2015 ◽  
Vol 66 (4) ◽  
pp. 332 ◽  
Author(s):  
Lindsay W. Bell ◽  
Julianne M. Lilley ◽  
James R. Hunt ◽  
John A. Kirkegaard

Interest is growing in the potential to expand cropping into Australia’s high-rainfall zone (HRZ). Dual-purpose crops are suited to the longer growing seasons in these environments to provide both early grazing for livestock and later regrow to produce grain. Grain yield and grazing potential of wheats of four different maturity types were simulated over 50 years at 13 locations across Australia’s HRZ, and sowing date, nitrogen (N) availability and crop density effects were explored. Potential grazing days on wheat were obtained by simulating sheep grazing crops to Zadoks growth stage Z30 at 25 dry sheep equivalents (DSE)/ha. Optimal sowing dates for each maturity type at each location were matched to the flowering window during which risk of frost and heat stress was lowest. Overall, we found significant national potential for dual-purpose use of winter wheat cultivars across Australia’s HRZ, with opportunities identified in all regions. Simulated mean wheat yields exceeded 6 t/ha at most locations, with highest mean grain yields (8–10 t/ha) in southern Victoria, and lower yields (5–7 t/ha) in the south-west of Western Australia (WA) and central and northern New South Wales (NSW). Highest grazing days were from winter cultivars sown early (March–mid-April), which could provide 1700–3000 DSE-days/ha of grazing across HRZ locations; this was 2–3 times higher than could be obtained from grazing spring cultivars (200–800 DSE-days/ha). Sowing date was critical to maximise both grazing and grain yield potential from winter cultivars; each 1-week delay in sowing after 8 March reduced grazing by 200–250 DSE-days/ha and grain yield by 0.45 t/ha. However, in Mediterranean climates, a lower frequency of early sowing opportunities before mid-April (<30% of years) is likely to limit the potential to use winter cultivars. Prospects to graze shorter season spring cultivars that fit later sowing windows require further examination in south-west WA, the slopes of NSW and southern Queensland.


2016 ◽  
Vol 67 (1) ◽  
pp. 117 ◽  
Author(s):  
Lindsay W. Bell ◽  
Julianne M. Lilley ◽  
James R. Hunt ◽  
John A. Kirkegaard

Interest is growing in the potential to expand cropping into Australia's high-rainfall zone (HRZ). Dual-purpose crops are suited to the longer growing seasons in these environments to provide both early grazing for livestock and later regrow to produce grain. Grain yield and grazing potential of wheats of four different maturity types were simulated over 50 years at 13 locations across Australia's HRZ, and sowing date, nitrogen (N) availability and crop density effects were explored. Potential grazing days on wheat were obtained by simulating sheep grazing crops to Zadoks growth stage Z30 at 25 dry sheep equivalents (DSE)/ha. Optimal sowing dates for each maturity type at each location were matched to the flowering window during which risk of frost and heat stress was lowest. Overall, we found significant national potential for dual-purpose use of winter wheat cultivars across Australia's HRZ, with opportunities identified in all regions. Simulated mean wheat yields exceeded 6t/ha at most locations, with highest mean grain yields (8–10t/ha) in southern Victoria, and lower yields (5–7t/ha) in the south-west of Western Australia (WA) and central and northern New South Wales (NSW). Highest grazing days were from winter cultivars sown early (March–mid-April), which could provide 1700–3000 DSE-days/ha of grazing across HRZ locations; this was 2–3 times higher than could be obtained from grazing spring cultivars (200–800 DSE-days/ha). Sowing date was critical to maximise both grazing and grain yield potential from winter cultivars; each 1-week delay in sowing after 8 March reduced grazing by 200–250 DSE-days/ha and grain yield by 0.45t/ha. However, in Mediterranean climates, a lower frequency of early sowing opportunities before mid-April (


2018 ◽  
Vol 156 (10) ◽  
pp. 1163-1174 ◽  
Author(s):  
W. S. Budzyński ◽  
K. Bepirszcz ◽  
K. J. Jankowski ◽  
B. Dubis ◽  
A. Hłasko-Nasalska ◽  
...  

AbstractA field experiment with the 35–1 fractional factorial design and five factors (k = 5) at three levels (s = 3) was performed in 2007–2010 at the Agricultural Experiment Station in Bałcyny, north-eastern (NE) Poland. The results of the experiment carried out under the agro-ecological conditions of NE Poland confirmed the high yield potential of common wheat and satisfactory yield potential of spelt and durum wheat. On average, durum wheat and spelt yields were 2.14 and 2.55 t/ha lower, respectively, than common wheat yields. Sowing date was not correlated with the yields of analysed Triticum species. Seed rate (350, 450 and 550 seeds/m2) had no significant influence on the grain yield of winter cultivars of common wheat, durum wheat and spelt. Common wheat cv. Oliwin and durum wheat cv. Komnata were characterized by the highest yields in response to nitrogen (N) fertilizer rates calculated based on the Nmin content of soil. An increase in the spring fertilizer rate by 40 kg N/ha in excess of the balanced N rate was not justified because it did not induce a further increase in the grain yield of common wheat and durum wheat. The grain yield of spelt cv. Schwabenkorn continued to increase in response to the highest rate of N fertilizer in spring (40 kg N/ha higher than the optimal rate). Intensified fungicide treatments improved grain yield in all Triticum species.


2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Dil Bahadur Gurung ◽  
Balram Bhandari ◽  
Jiban Shrestha ◽  
Mahendra Prasad Tripathi

Genotypic yield potential of maize varieties is greatly affected by sowing dates. In order to investigate the effects of sowing dates and varieties on the grain yield of maize, the field experiment was carried out at research field of National Maize Research Program (NMRP), Rampur, Chitwan, Nepal from April 2009 to March 2010.  Three varieties namely Rampur Composite, Arun-2 and Gaurav were sown at every week. The results of experiment showed that interaction effect of variety and sowing date on grain yield of maize was significant. Rampur Composite produced highest grain yield (6.1 t/ha) in August and lowest yield (2.6 t/ha) in May. Similarly Arun-2 produced highest yield (4.6 t/ha) in August and lowest yield (2.1 t/ha) in May. Gaurav produced highest grain yield (5.1 t/ha) in September followed by 4.9, 4.8 and 4.6 t/ha in February, July and August respectively and lowest yield (1.5 t/ha) in November. The sowing date was highly significant on grain production. The highest grain production was 5.1 t/ha in August followed by in February (4.9 t/ha), September (4.6 t/ha) and March (4.4 t/ha) respectively. The lowest grain yield was produced in May (2.4 t/ha). Therefore it was concluded that August planting was best for higher grain production of maize varieties (Rampur Composite, Arun-2 and Gaurav) in terai region of Nepal.


2004 ◽  
Vol 44 (1) ◽  
pp. 43 ◽  
Author(s):  
M. J. Robertson ◽  
J. F. Holland ◽  
R. Bambach

Sowing date is an important determinant of yield in canola. The arrival at an optimum sowing time will depend on trade-offs between lowered frost risk with delayed sowing and lowered yield potential. A comprehensive analysis of response to sowing date has not been conducted for northern environments, a new region for canola production. The aim of this study was to analyse the response of phenology, yield and oil content of current cultivars of canola to sowing date (April–September) in north-eastern Australia, using 17 sowings from Tamworth (31.09°S) to Lawes (27.55°S). Three cultivars were studied: an early and late flowering canola and an advanced breeding line of Indian mustard. For all 3 genotypes, a delay in sowing shortened the time to 50% flowering and to maturity, while differences among the genotypes in time to flowering for sowing dates around 15 May reflected their known differences in phenological development. For sowings at Tamworth beyond 15 May, a 1 day delay in sowing delayed flowering by 0.42, 0.42 and 0.37 days in Indian mustard, Monty and Oscar, respectively. Delay in maturity was 0.58, 0.56 and 0.54 days per day delay in sowing date. Yield and oil content penalties due to delayed sowing were similar to those found previously in other Australian environments. The decline of grain yield with delay in sowing date could be largely explained by the decline in biomass at maturity, while for oil content it could be related positively to harvest index and seed size, and negatively to temperature conditions post-anthesis. Indian mustard had a lower harvest index, grain yield and oil content than both canola cultivars. Oil content exceeded 40% in canola in half of the sowings. Information on the response of oilseed Brassicas to sowing date can be used to quantify the trade-offs between frost risk and crop productivity with sowing date for different cultivar types.


2001 ◽  
Vol 49 (3) ◽  
pp. 293-297
Author(s):  
S. O. Bakare ◽  
M. G. M. Kolo ◽  
J. A. Oladiran

There was a significant interaction effect between the variety and the sowing date for the number of productive tillers, indicating that the response to sowing date varied with the variety. A significant reduction in the number of productive tillers became evident when sowing was delayed till 26 June in the straggling variety as compared to sowing dates in May. Lower numbers of productive tillers were also recorded when the sowing of the erect variety was further delayed till 10 July. The grain yield data showed that it is not advisable to sow the straggling variety later than 12 June, while sowing may continue till about 26 June for the erect variety in the study area.


Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 69
Author(s):  
Cailong Xu ◽  
Ruidong Li ◽  
Wenwen Song ◽  
Tingting Wu ◽  
Shi Sun ◽  
...  

Increasing planting density is one of the key management practices to enhance soybean yield. A 2-yr field experiment was conducted in 2018 and 2019 including six planting densities and two soybean cultivars to determine the effects of planting density on branch number and yield, and analyze the contribution of branches to yield. The yield of ZZXA12938 was 4389 kg ha−1, which was significantly higher than that of ZH13 (+22.4%). In combination with planting year and cultivar, the soybean yield increased significantly by 16.2%, 31.4%, 41.4%, and 46.7% for every increase in density of 45,000 plants ha−1. Yield will not increase when planting density exceeds 315,000 plants ha−1. A correlation analysis showed that pod number per plant increased with the increased branch number, while pod number per unit area decreased; thus, soybean yield decreased. With the increase of branch number, the branch contribution to yield increased first, and then plateaued. ZH13 could produce a high yield under a lower planting density due to more branches, while ZZXA12938 had a higher yield potential under a higher planting density due to the smaller branch number and higher tolerance to close planting. Therefore, seed yield can be increased by selecting cultivars with a little branching capacity under moderately close planting.


2021 ◽  
Vol 10 (6) ◽  
pp. 396
Author(s):  
Ümit Yıldırım

In this study, geographic information system (GIS)-based, analytic hierarchy process (AHP) techniques were used to identify groundwater potential zones to provide insight to decisionmakers and local authorities for present and future planning. Ten different geo-environmental factors, such as slope, topographic wetness index, geomorphology, drainage density, lithology, lineament density, rainfall, soil type, soil thickness, and land-use classes were selected as the decision criteria, and related GIS tools were used for creating, analysing and standardising the layers. The final groundwater potential zones map was delineated, using the weighted linear combination (WLC) aggregation method. The map was spatially classified into very high potential, high potential, moderate potential, low potential, and very low potential. The results showed that 21.5% of the basin area is characterised by high to very high groundwater potential. In comparison, the very low to low groundwater potential occupies 57.15%, and the moderate groundwater potential covers 21.4% of the basin area. Finally, the GWPZs map was investigated to validate the model, using discharges and depth to groundwater data related to 22 wells scattered over the basin. The validation results showed that GWPZs classes strongly overlap with the well discharges and groundwater depth located in the given area.


1991 ◽  
Vol 18 (1) ◽  
pp. 53 ◽  
Author(s):  
PC Pheloung ◽  
KHM Siddique

Field experiments were conducted in the eastern wheat belt of Western Australia in a dry year with and without irrigation (1987) and in a wet year (1988), comparing three cultivars of wheat differing in height and yield potential. The aim of the study was to determine the contribution of remobilisable stem dry matter to grain dry matter under different water regimes in old and modern wheats. Stem non-structural carbohydrate was labelled with 14C 1 day after anthesis and the activity and weight of this pool and the grain was measured at 2, 18 and 58 days after anthesis. Gutha and Kulin, modern tall and semi-dwarf cultivars respectively, yielded higher than Gamenya, a tall older cultivar in all conditions, but the percentage reduction in yield under water stress was greater for the modern cultivars (41, 34 and 23%). In the grain of Gamenya, the increase in 14C activity after the initial labelling was highest under water stress. Generally, loss of 14C activity from the non-structural stem dry matter was less than the increase in grain activity under water stress but similar to or greater than grain activity increase under well watered conditions. Averaged over environments and cultivars, non-structural dry matter stored in the stem contributed at least 20% of the grain dry matter.


2011 ◽  
Vol 62 (1) ◽  
pp. 1 ◽  
Author(s):  
R. J. Lawn ◽  
A. T. James

The purpose of this paper and its companion1 is to describe how, in eastern Australia, soybean improvement, in terms of both breeding and agronomy, has been informed and influenced over the past four decades by physiological understanding of the environmental control of phenology. This first paper describes how initial attempts to grow soybean in eastern Australia, using varieties and production practices from the southern USA, met with limited success due to large variety × environment interaction effects on seed yield. In particular, there were large variety × location, variety × sowing date, and variety × sowing date × density effects. These various interaction effects were ultimately explained in terms of the effects of photo-thermal environment on the phenology of different varieties, and the consequences for radiation interception, dry matter production, harvest index, and seed yield. This knowledge enabled the formulation of agronomic practices to optimise sowing date and planting arrangement to suit particular varieties, and underpinned the establishment of commercial production in south-eastern Queensland in the early 1970s. It also influenced the establishment and operation over the next three decades of several separate breeding programs, each targeting phenological adaptation to specific latitudinal regions of eastern Australia. This paper also describes how physiological developments internationally, particularly the discovery of the long juvenile trait and to a lesser extent the semi-dwarf ideotype, subsequently enabled an approach to be conceived for broadening the phenological adaptation of soybeans across latitudes and sowing dates. The application of this approach, and its outcomes in terms of varietal improvement, agronomic management, and the structure of the breeding program, are described in the companion paper.


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