Modelling crop growth and grain yield in maize cultivation

Author(s):  
Alam Sher ◽  
◽  
Xiaoli Liu ◽  
Jincai Li ◽  
Youhong Song ◽  
...  
2002 ◽  
Vol 42 (6) ◽  
pp. 717 ◽  
Author(s):  
R. A. Sudmeyer ◽  
P. R. Scott

This paper, which is the second in a series of three, describes dryland crop growth and yields in a windbreak bay in south-western Australia and relates changes to microclimate modification by the windbreaks. Over the 4 years of this trial, above ground biomass and the development rate of crops 3–20 times the tree height from the windbreak (H) were similar to crops growing in unsheltered conditions (more than 20 H from the windbreaks). Grain yield was 16–30% higher between 3 H and 20 H than at more than 20 H in 1994, the driest year on record for the district, in other years yield was largely unchanged. In contrast, above ground biomass growth was consistently less within 3 H than further from the windbreaks and grain yield within 3 H was 19–27% less than unsheltered yield. Water use by the trees is the most likely cause of reduced yield within 3 H. Over the 4 years, mean grain yield between 0.5 H and 20 H was 3.8% greater than yield at more than 20 H. This increase was largely due to the yield increase in 1994. As 5.4% of the paddock was directly occupied by, or uncropped next to, the windbreaks, there was a net yield decrease of 2.8% over 4 years compared to estimated production from a similar area with no windbreaks. The principle benefits of the windbreaks were reducing evaporative demand in extremely dry years and protection against extreme wind events. These benefits must be weighed against the costs of establishing and maintaining windbreak systems.


2014 ◽  
Vol 6 (4) ◽  
pp. 188 ◽  
Author(s):  
Joseph Adigun ◽  
A. O. Osipitan ◽  
Segun Toyosi Lagoke ◽  
Raphael Olusegun Adeyemi ◽  
Stephen Olaoluwa Afolami

Weed problem appears to be the most deleterious factor causing between 25 and 60% reduction in potential yield of cowpea. Field trials were therefore conducted to study the effect of inter-row spacing and period of weed interference on growth and yield of cowpea (Vigna unguiculata (L) Walp) at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (07° 15'; 03° 25' E) in South Western Nigeria during the early and late wet seasons of 2009. The experiment consisted of eight main plots of weed interference which included initial weed removal for 3, 6, 9, and 12 weeks after sowing (WAS) and subsequently weed –infested until harvest as well as initial weed infestation for corresponding periods and thereafter kept weed free until harvest. There were also sub-plot treatments of three inter-row spacing of 60, 75, and 90 cm. All treatments in different combinations were laid out in a split-plot design with three replications. In both trials, the use of inter-row spacing of 60 cm resulted in significant reduction in weed growth as evident in lower weed dry matter production and subsequent higher cowpea pod and grain yields than those of 75 and 90 cm inter-row spacing. Initial weed infestation of up to 3 WAS did not have any adverse effect on crop growth and cowpea grain yields provided the weeds were subsequently removed. On the other hand, cowpea grain yield loss was not significantly averted by keeping the crop weed free for only 3 WAS without subsequent weed removal. In this study, initial weed-infestation for 6 WAS and beyond significantly depressed various crop growth parameter and cowpea grain yield compared with the crop kept weed free throughout its life cycle. In order to obtain optimum yields similar to that of the weed free cowpea field, it was required to keep the crop weed free for 6 WAS and beyond. However, frequent weeding beyond 9 weeks after sowing did not improve cowpea yield significantly and as a matter of fact it may even result in reduction of cowpea grain yield due to mechanical damage of hoe weeding. The practical implication of this finding is that early weeding starting from 3 WAS is very crucial for cowpea production while the critical period of weed removal for optimum yield in cowpea is between 3 and 9 WAS in the forest-savannah transitional zone of south Western Nigeria.


2020 ◽  
Author(s):  
Yaojun Zhang ◽  
Jiaqi Ding ◽  
Hong Wang ◽  
Lei Su ◽  
Cancan Zhao

Abstract Background: Environmental stress is a crucial factor restricting plant growth as well as crop productivity, thus influencing the agricultural sustainability. Biochar addition is proposed as an effective management to improve crop performance. However, there were few studies focused on the effect of biochar addition on crop growth and productivity under interactive effect of abiotic stress (e.g., drought and salinity). This study was conducted with a pot experiment to investigate the interaction effects of drought and salinity stress on soybean yield, leaf gaseous exchange and water use efficiency (WUE) under biochar addition. Results: Drought and salinity stress significantly depressed soybean phenology (e.g. flowering time) and all the leaf gas exchange parameters, but had inconsistent effects on soybean root growth and WUE at leaf and yield levels. Salinity stress significantly decreased photosynthetic rate, stomatal conductance, intercellular CO2 concentration and transpiration rate by 20.7%, 26.3%, 10.5% and 27.2%, respectively. Lower biomass production and grain yield were probably due to the restrained photosynthesis under drought and salinity stress. Biochar addition significantly enhanced soybean grain yield by 3.1-14.8%. Drought stress and biochar addition significantly increased WUE-yield by 27.5% and 15.6%, respectively, while salinity stress significantly decreased WUE-yield by 24.2%. Drought and salinity stress showed some negative interactions on soybean productivity and leaf gaseous exchange. But biochar addition alleviate the negative effects on soybean productivity and water use efficiency under drought and salinity stress. Conclusions: The results of the present study indicated that drought and salinity stress could significantly depress soybean growth and productivity. There exist interactive effects of drought and salinity stress on soybean productivity and water use efficiency, while we could employ biochar to alleviate the negative effects. We should consider the interactive effects of different abiotic restriction factors on crop growth thus for sustainable agriculture in the future.


Author(s):  
Ahmad Raza ◽  
Muhammad Nawaz ◽  
Muhammad U. Chattha ◽  
Imran Khan ◽  
Muhammad B. Chattha ◽  
...  

Weeds are major threat to global wheat production and cause serious threat to food security. Likewise, water scarcity is also a major threat to food production and its intensity is continuously soaring up across the globe. Organic mulches have potential to reduce weeds growth and conserve the soil moisture thus ensures the better crop growth and yield. Therefore, present study was conducted to compare the performance of different organic mulches in improving wheat growth and productivity. The study was comprised of different organic mulches; M1= No mulch (control) M2= maize straw mulch, M3= wheat straw mulch, M4= sorghum straw mulch and M5= rice straw mulch and three nitrogen levels N1 = 90 kg, N2 = 120 kg and N3= 150 kg/ha. The results indicated that both organic mulches and N rates had significant impact on growth, and yield traits. The maximum leaf area index (LAI), crop growth rate (CGR), productive tillers (307 m-2), grains/spike (46.22), 1000 grain weight (42.33 g) biological yield (13.76 t/ha) and grain yield 4.75 t/ha was obtained with sorghum straw mulch and minimum productive tillers (255.33 m-2), grains/spike (36.22), biological yield (11.46 t/ha) and grain yield (3.59 t/ha) was recorded in no mulch (control). Among nitrogen levels maximum productive tillers (290.6 m-2), grains/spike (42.80), 1000 grain weight (40.65 g), biological yield (13.44 t/ha) and grain yield (4.32 t/ha) was obtained with 150 kg/ha N and minimum productive tillers (274 m-2), grains/spike (38.13), 1000 grain weight (36.94 g) biological yield (11.98 t/ha) and grain yield (3.90 t/ha) was obtained with 90 N kg/ha. Thus, farmers can use sorghum straw mulch and N (150 kg ha-1) to improve the wheat productivity. However, farmers must be educated by government institute and adoptive research farms in order to understand and adaption of this approach.


1971 ◽  
Vol 77 (3) ◽  
pp. 445-452 ◽  
Author(s):  
R. W. Willey ◽  
R. Holliday

SUMMARYTwo barley experiments are described in which a range of plant populations were shaded during different periods of development. Shading during the ear development period caused considerable reductions in grain yield, largely by reducing the number of grains per ear. Shading during the grain-filling period caused no reduction in grain yield. It is suggested that under conditions of these experiments there was probably a potential surplus of carbohydrate available for grain filling and that grain yield was largely determined by the storage capacity of the ears. The importance of the number of grains per ear as an indicator of individual ear capacity is emphasized.The effects of plant population on grain yield and its components are also examined. It is concluded that the number of grains per ear is the component having greatest influence on the decrease in grain yield at above-optimum populations and attention is again drawn to the possible importance of ear capacity. It is argued that on an area basis the number of grains per unit area may give a good indication of ear capacity. Examination of this parameter shows a close relationship with grain yield per unit area for both the shading and population treatments. It is particularly evident that a decrease in grain yield at high populations was associated with a comparable decrease in the number of grains per unit area. It is suggested that this decrease in grain number may be due to a lower production of total dry matter during ear development rather than an unfavourable partitioning of this dry matter between the ear and the rest of the plant. This lower production of total dry matter is attributed to the crop growth rates of the higher populations having reached their peak and then having declined before the end of the ear development period. This crop growth rate pattern, through its effect on grain number per unit area, is put forward as the basic reason why, in the final crop, grain yield per unit area decreases at above-optimum populations.


2020 ◽  
Vol 15 (1) ◽  
pp. 106-122
Author(s):  
J. Alam ◽  
R. K. Panda

 Any change in climate will have implications for climate-sensitive systems such as agriculture, forestry and some other natural resources. Changes in solar radiation, temperature and precipitation will produce changes in crop yields and hence economics of agriculture. It is possible to understand the phenomenon of climate change on crop production and to develop adaptation strategies for sustainability in food production, using a suitable crop simulation model. CERES-Maize model of DSSAT v4.0 was used to simulate the maize yield of the region under climate change scenarios using the historical weather data at Kharagpur (1977-2007), Damdam (1974-2003) and Purulia (1986-2000), West Bengal, India. The model was calibrated using the crop experimental data, climate data and soil data for two years (1996-1997) and was validated by using the data of the year 1998 at Kharagpur. The change in values of weather parameters due to climate change and its effects on the maize crop growth and yield was studied. It was observed that increase in mean temperature and leaf area index have negative impacts on maize yield. When the maximum leaf area index increased, the grain yield was found to be decreased. Increase in CO2 concentration with each degree incremental temperature decreased the grain yield but increase in CO2 concentration with fixed temperature increased the maize yield. Adjustments were made in the date of sowing to investigate suitable option for adaptation under the future climate change scenarios. Highest yield was obtained when the sowing date was advanced by a week at Kharagpur and Damdam whereas for Purulia, the experimental date of sowing was found to be beneficial.


2009 ◽  
Vol 60 (9) ◽  
pp. 870 ◽  
Author(s):  
R. D. Armstrong ◽  
J. Fitzpatrick ◽  
M. A. Rab ◽  
M. Abuzar ◽  
P. D. Fisher ◽  
...  

A major barrier to the adoption of precision agriculture in dryland cropping systems is our current inability to reliably predict spatial patterns of grain yield for future crops for a specific paddock. An experiment was undertaken to develop a better understanding of how edaphic and climatic factors interact to influence the spatial variation in the growth, water use, and grain yield of different crops in a single paddock so as to improve predictions of the likely spatial pattern of grain yields in future crops. Changes in a range of crop and soil properties were monitored over 3 consecutive seasons (barley in 2005 and 2007 and lentils in 2006) in the southern section of a 167-ha paddock in the Mallee region of Victoria, which had been classified into 3 different yield (low, moderate, and high) and seasonal variability (stable and variable) zones using normalised difference vegetation index (NDVI) and historic yield maps. The different management zones reflected marked differences in a range of soil properties including both texture in the topsoil and potential chemical-physical constraints in the subsoil (SSCs) to root growth and water use. Dry matter production, grain yield, and quality differed significantly between the yield zones but the relative difference between zones was reduced when supplementary irrigation was applied to barley in 2005, suggesting that some other factor, e.g. nitrogen (N), may have become limiting in that year. There was a strong relationship between crop growth and the use of soil water and nitrate across the management zones, with most water use by the crop occurring in the pre-anthesis/flowering period, but the nature of this relationship appeared to vary with year and/or crop type. In 2006, lentil yield was strongly related to crop establishment, which varied with soil texture and differences in plant-available water. In 2007 the presence of soil water following a good break to the season permitted root growth into the subsoil where there was evidence that SSCs may have adversely affected crop growth. Because of potential residual effects of one crop on another, e.g. through differential N supply and use, we conclude that the utility of the NDVI methodology for developing zone management maps could be improved by using historical records and data for a range of crop types rather than pooling data from a range of seasons.


1984 ◽  
Vol 8 ◽  
pp. 207-227 ◽  
Author(s):  
D.J. Midmore ◽  
P.M. Cartwright ◽  
R.A. Fischer

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