scholarly journals Calibration and test of the cropgro-dry bean model for edaphoclimatic conditions in the savanas of Central Brazil

2002 ◽  
Vol 59 (4) ◽  
pp. 723-729 ◽  
Author(s):  
Elza Jacqueline Leite Meireles ◽  
Antonio Roberto Pereira ◽  
Paulo Cesar Sentelhas ◽  
Luis Fernando Stone ◽  
Francisco José Pfeilsticker Zimmermann

Simulation models are important tools for the analysis of cultivated systems to estimate the performance of crops in different environments. The CROPGRO- model (DSSAT) was calibrated and validated using Carioca bean (Phaseolus vulgaris L.) to estimate yield and the development of the crop, sown in three row spacings (0.4, 0.5, and 0.6 m) and two fertilization rates (300 and 500 kg ha-1 of 4-30-16 N-P-K), in Santo Antônio de Goiás, GO, Brazil. To calibrate the model a combination of the genetic coefficients that characterize the phenology and morphology of the dry bean crop was used to obtain the best possible fit between predicted and observed anthesis and physiological maturity dates, leaf area index (LAI), total dry matter (TDM), yield components, and grain yield for the 0.6 m row spacing. To test the model the experimental records of the 0.4 and 0.5 m row spacings were used. In both, calibration and test, the performance of the model was evaluated plotting observed and predicted values of LAI and TDM versus time, using the r², and the agreement index (d) as statistical criteria. In relation to yield and yield components the percent difference between the observed and predicted data was calculated. The model appeared to be adequate to simulate phenology, grain yield and yield components for the Carioca bean cultivar, related to different levels of fertilization and row spacing, either during calibration or the testing phase. During the test, the grain yield was overestimated by less than 15.4%, indicating a potential use for the calibrated model in assessing climatic risks in this region.

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11668
Author(s):  
Ke Wu ◽  
Izhar Ali ◽  
Huimin Xie ◽  
Saif Ullah ◽  
Anas Iqbal ◽  
...  

The current farming system in China is heavily reliant on synthetic fertilizers, which adversely affect soil quality and crop production. Therefore, the aim of this study was to assess the effect of different nitrogen (N) and phosphorous (P) fertilizer application rate on the growth, yield, and yield components of rice cultivars in the Binyang, Beiliu and Liucheng sites of southern China in the early (March to July) and late season (August to December). The study consisted of three fertilization regimes—CK (N0P0); N180P90 (180 kg N + 90 kg P2O5 ha−1) and N90P45 (90 kg N ha−1 + 45 kg P2O5)—conducted at each of three different experimental sites with four cultivars (Baixang 139, Y Liangyou 1, Guiyu 9, and Teyou 582). Results showed that the leaf area index (LAI) was 38.8% found higher in Guiyu 9 compared with Baxiang at reduced fertilization (N90P45). N90P45 resulted higher dry matter production at the heading (9411.2 kg ha−1) and maturity (15319.5 kg ha−1) stages in Teyou 582 at Beiliu. Fertilization (N180P90) had higher effective panicle number (4,158,800 panicle ha−1) and grains panicle−1 (113.84 grains) compared with other treatments. Teyou 582 treated with N90P45 and Y Liangyou 1 treated with N180P90 improved seed setting rate average by 82.91% and 72.17% compared with other treatments at Beiliu in both seasons, respectively. N0P0 and N90P45 increased the thousand-grain weight (TGW) of Y Liangyou 1 at Binyang (27.07 g) and Liucheng (27.84 g) during the early and late seasons, respectively. In Beiliu, the N90P45 treatment (6611.7 kg ha−1) of Teyou 582 increased grain yield compared with other treatments. Overall, our results suggested that reducing N and P at the ratio of 90:45 kg ha−1 in Teyou 582 and Y Liangyou 1 could increase rice grain yield and yield components.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Tolera Abera ◽  
Tolessa Debele ◽  
Dagne Wegary

Yield of maize hybrids could be low when grown below optimum management practices. Use of improved varieties and optimum nitrogen fertilizer application practices are unlocking the high yielding potential of hybrids maize. With these in view, a field experiment was executed on farmers’ field to determine the effect of varieties and nitrogen fertilizer rate on yield and yield components of maize in two cropping seasons. It is laid out with randomized complete block design in factorial arrangement with three replications. Five maize varieties (BH-540, BH-543, BH-661, BH-660, and BH-140) as main factor and two levels of nitrogen (55 and 110 Kg N ha−1) as subfactor were used with one maize variety (BH-543) without fertilizer as control. Leaf area and leaf area index of maize varieties were significantly affected by application of nitrogen fertilizer rates. Interaction of maize varieties with nitrogen fertilizer rates significantly affected all yield and yield components of maize. Application of half and full recommended nitrogen fertilizer produced mean grain yield advantages of 31 and 41% over control. Therefore, application of half and full recommended nitrogen fertilizer for improved maize varieties has significantly improved grain yield and recommended for maize production in midaltitude area of western Ethiopia.


Author(s):  
Tran Xuan Minh ◽  
Nguyen Cong Thanh ◽  
Tran Hau Thin ◽  
Nguyen Thi Tieng ◽  
Nguyen Thi Huong Giang

Background: Understanding the effects of different plant densities and row spacing on yield and yield components of peanut L14 is essential for designing and adjusting management practices to improve yield. Methods: Five planting densities were tested in Randomized Complete Block Design with three replications in 2019 spring crop on the coastal sandy land area in Dien Chau district, Nghe An, Vietnam. Result: The different density treatments affect the growth, development and yield of the peanut variety L14. With increasing plant density, the number of pod per plant, 100 pods weight, 100 seeds weight decreased, whereas plant height, leaf area index, dry matter production increased. Population yield increased with increasing plant density from the lowest density of 25 plants m-2 (2.78 tons ha-1), reached the highest at 35 plants m-2 (4.53 tons ha-1), then decreasing with increasing plant density. Peanut variety L14 is grown in plant densities and row spacing of 35 plants m-2 (25 cm × 25 cm) and 40 plants m-2 (25 cm × 20 cm) are most appropriate; plants grow, develop better and give a higher yield than other densities under the same conditions.


2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Abduraman Nure ◽  
Husen Aman Jara

Corn is an important cereal crop in Ethiopia due to its use as a source of food security. However, its productivity is limited by insufficient application of the NPS fertilizer and different row spacing. A field trial was carried out to assess the effects of the application of different NPS fertilizer quantities and inter row spacing on the growth, yield components and yield of maize and the cost-benefit analysis of the NPS compound fertilizer application on the yield of maize in the main growing season 2019/2020.The study was arranged in a factorial combination of five levels of NPS fertilizers (0, 50, 100, 150 and 200 kg NPS ha-1) and four inter row spacing (55 cm, 65 cm, 75 cm and 85 cm). in a randomized complete block design with three replications. The consequence showed the main result of the NPS fertilizer had a highly significant (p <0.01) effect on days up to 50% anthesis, days up to 50% silk formation, 90% physiological maturity, leaf area, leaf area index, number of plants at harvest, the number of grains per ear was determined from the main effects of NPS fertilizer of 200 kg NPS ha-1. The interaction effects of NPS and row spacing have highly significant (p <0.01) effects on the number of ears per plant, number of ears per hectare, ear length, agronomic effectiveness and grain yield were obtained when using 150 kg. measured NPS ha-1 at 75 cm row spacing. The highest economic (91,608 Birr ha-1) and a higher MRR (1745%) resulted from the 150 kg NPS ha-1 and 75 cm row spacing. Thus, it should be noted that the application of 150 kg NPS ha-1 with a row spacing of 75 cm was both agronomic and cost-effective for the grain yield of the Melkassa-II in the study area.


2018 ◽  
Vol 39 (1) ◽  
pp. 393
Author(s):  
Tiago Zoz ◽  
Fábio Steiner ◽  
André Zoz ◽  
Deise Dalazen Castagnara ◽  
Travis Wilson Witt ◽  
...  

Understanding the influence of row spacing and plant density on grain yield and yield components of crambe is critical in order to obtain higher grain yields. Therefore, the objective of this study was to evaluate the effects of row spacing and plant density on grain yield and its components in crambe in two distinct regions of Brazil (Marechal Candido Rondon-PR, MCR-PR, and Botucatu-SP, BTU-SP). Narrow and wide row spacing (0.20 and 0.40 m) combined with four plant densities (15, 25, 35, and 45 plants m-1) were evaluated in a randomized block layout with four replications in a 2 × 4 factorial design. The experiment at BTU-SP was run under rainfed conditions with supplementary irrigation, whereas the experiment at MCR-PR was run under rainfed conditions without supplementary irrigation. Both experiments were run in soils classified as Oxisols. There was no interaction between row spacing and plant density. Highest grain yield with supplementary irrigation was observed at 0.20 m row spacing. Without irrigation, row spacing did not affect grain yield owing to the plasticity of crop. The highest grain yield was observed with approximately 30 plants m-1 at both experimental locations. A strong negative correlation was observed between final plant population and number of grains per plant. There was high plant mortality, particularly at high plant densities cultivated under irrigation. Higher mortality occurred because of high intraspecific competition and a larger disease incidence due to the higher humidity in the irrigated experiment. A mechanism of self-adjustment by plant density was observed in crambe, with its intensity dependent on plant density and environmental conditions, such as water and nutrient availability and light incidence.


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