Bromide redistribution as influenced by landscape morphology and pedogenic properties in a variable glacial till landscape: A qualitative examination

2008 ◽  
Vol 88 (4) ◽  
pp. 477-490 ◽  
Author(s):  
D A Whetter ◽  
P R Bullock ◽  
L G Fuller

Redistribution of water and associated solutes in undulating to hummocky landscapes affects crop yield via losses of valuable nutrients and negatively impacts groundwater quality. The objective of this study was to determine the influence of qualitative soil-landscape complexes on vertical and lateral redistribution of solutes in a variable glacial till landscape under zero tillage agricultural management by employing a bromide tracer. Tracer plots were established in the fall of 1999 within three sites comprising three representative soil-slope associations. Values of soil development indicators (A horizon thickness, solum thickness, depth to CaCO3, profile development index and organic carbon) generally increased from crest to midslope to depression. Further to this, the occurrence and thickness of eluvial and illuvial horizons increased from crest to midslope to depression. Well-developed, clay-coated blocky Bt horizons with vertical cracking and overlying Ae horizons in depressions appeared to have favoured rapid, downward vertical bromide redistribution. Crest positions were the least anisotropic and vertical redistribution was more important than lateral redistribution at this position. A combination of topographic and pedologic factors resulted in more lateral redistribution at the midslope position relative to crests and depressions. Bromide recovery rates in the top 60 cm of the soil profile indicated that most of the recovered bromide remained within that depth following spring runoff, but had mostly leached below that depth after the growing season, particularly at the depression position. Low bromide recovery rates in the top 30 cm following spring runoff, indicated that reduced availability of fall-applied nutrients for early crop growth could be expected at crest and depression positions following spring runoff. Bromide redistribution was important during both spring recharge and over the growing season at the depression position. Bromide movement below crop rooting depths and into shallow groundwater sources provides evidence that fall-applied nutrients can enter groundwater following both spring melt and growing season runoff in depressional landscape positions, especially in recharge areas. Management practices to reduce over-application of soluble nutrients and surface water accumulation, or both, in depressional areas may be an effective means to lower the risk of groundwater contamination with soluble nutrients without jeopardizing crop yield potential across the majority of the landscape positions in undulating to hummocky glacial till terrain. Key words: Solute redistribution, bromide tracer, soil properties, topography, landscape

2005 ◽  
Vol 85 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Cynthia Grant ◽  
Shabtai Bittman ◽  
Marcia Montreal ◽  
Christian Plenchette ◽  
Christian Morel

Plants require adequate P from the very early stages of growth for optimum crop production. Phosphorus supply to the crop is affected by soil P, P fertilizer management and by soil and environmental conditions influencing P phytoavailability and root growth. Phosphorus uptake in many crops is improved by associations with arbuscular mycorrhizal fungi. Cropping system and long-term input of P through fertilizers and manures can influence the amount and phytoavailability of P in the system and the development of mycorrhizal associations. Optimum yield potential requires an adequate P supply to the crop from the soil or from P additions. Where early-season P supply is low, P fertilization may improve P nutrition and crop yield potential. Alternately, under low-P conditions, encouragement of arbuscular mycorrhizal associations may enhance P uptake by crops early in the growing season, improving crop yield potential and replacing starter fertilizer P applications. Soil P supply that exceeds P requirements of the crop may preclude mycorrhizal development. To encourage arbuscular mycorrhizal association, threshold levels of soil solution P that restrict mycorrhizal development must not be exceeded. Sustainable P management practices must be applied both in conventional and in alternative biologically based agricultural systems. Key words: Microbiology, fertility, colonization


2019 ◽  
Vol 56 (Special) ◽  
pp. 82-91 ◽  
Author(s):  
LV Subba Rao ◽  
RA Fiyaz ◽  
AK Jukanti ◽  
G Padmavathi ◽  
J Badri ◽  
...  

India is the second largest producer of rice in the world and it is the most important staple food grain. All India Coordinated Rice Improvement Project (AICRIP) was initiated with objective of conducting multi-location trials to identify suitable genotypes of high yield potential along with appropriate crop management practices. Since its inception AICRIP contributed significantly in meeting the growing demand both within and outside India. Significant progress has been achieved through AICRIP in terms of varietal release thereby increasing the crop productivity and also meeting the food and nutritional security. This paper makes a sincere effort in bringing out the significant achievements/milestones achieved under the AICRIP program and also gives a few directions for widening the areas under AICRIP.


2021 ◽  
Vol 13 (16) ◽  
pp. 3069
Author(s):  
Yadong Liu ◽  
Junhwan Kim ◽  
David H. Fleisher ◽  
Kwang Soo Kim

Seasonal forecasts of crop yield are important components for agricultural policy decisions and farmer planning. A wide range of input data are often needed to forecast crop yield in a region where sophisticated approaches such as machine learning and process-based models are used. This requires considerable effort for data preparation in addition to identifying data sources. Here, we propose a simpler approach called the Analogy Based Crop-yield (ABC) forecast scheme to make timely and accurate prediction of regional crop yield using a minimum set of inputs. In the ABC method, a growing season from a prior long-term period, e.g., 10 years, is first identified as analogous to the current season by the use of a similarity index based on the time series leaf area index (LAI) patterns. Crop yield in the given growing season is then forecasted using the weighted yield average reported in the analogous seasons for the area of interest. The ABC approach was used to predict corn and soybean yields in the Midwestern U.S. at the county level for the period of 2017–2019. The MOD15A2H, which is a satellite data product for LAI, was used to compile inputs. The mean absolute percentage error (MAPE) of crop yield forecasts was <10% for corn and soybean in each growing season when the time series of LAI from the day of year 89 to 209 was used as inputs to the ABC approach. The prediction error for the ABC approach was comparable to results from a deep neural network model that relied on soil and weather data as well as satellite data in a previous study. These results indicate that the ABC approach allowed for crop yield forecast with a lead-time of at least two months before harvest. In particular, the ABC scheme would be useful for regions where crop yield forecasts are limited by availability of reliable environmental data.


2007 ◽  
Vol 145 (3) ◽  
pp. 223-227 ◽  
Author(s):  
M. P. REYNOLDS ◽  
P. R. HOBBS ◽  
H. J. BRAUN

Wheat is grown on 210 million ha throughout the world producing approximately 600 million tonnes of grain (10 year average; FAO 2005) and providing on average one fifth of the total calorific input of the world's population (FAO 2003). For some regions such as North Africa, Turkey and Central Asia, wheat provides half of total dietary energy intake. Of the cultivated wheat area, half is located in less developed countries where there have been steady increases in productivity since the green revolution, associated with genetic improvements in yield potential, resistance to diseases and adaptation to abiotic stresses (Reynolds & Borlaug 2006a, b) as well as better agronomic practices (Derpsch 2005). Nonetheless, challenges to wheat production are still considerable, especially in the developing world, not only because of increased demand but also because of the increased scarcity of water resources (Rosegrant 1997; WMO 1997), ever more unpredictable climates (Fischer et al. 2002), increased urbanization and loss of good quality land away from agriculture (Hobbs 2007), and decreased public sector investment in agriculture and rural affairs (Falcon & Naylor 2005). To meet demand in a sustainable way, more resources are required to breed a new generation of genetically improved cultivars as well as implement resource-conserving agronomic management practices.


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.


Plant Disease ◽  
2006 ◽  
Vol 90 (5) ◽  
pp. 657-662 ◽  
Author(s):  
William M. Wintermantel ◽  
Stephen R. Kaffka

Resistance to curly top disease caused by Beet curly top virus (BCTV) and related curtoviruses has been important to sustainable sugar beet (Beta vulgaris) production in the western United States for most of the last century. Recent advances in sugar beet genetics have led to the development of high-yielding cultivars, but these cultivars have little resistance to curly top disease. These cultivars are highly effective when disease management practices or environmental factors minimize curly top incidence, but can result in significant losses in years with early infection or abundant curly top. A greenhouse assay has been developed to rapidly test cultivars for a broad array of factors affecting performance in the presence of curly top. Previous studies have shown that sugar beet plants were more susceptible and losses more severe when seedlings were infected by BCTV, but less severe when plants were larger at the time of infection. To evaluate more precisely the relationship between age at infection, disease severity, virus accumulation, and yield loss in modern cultivars that were not bred for curly top resistance, individual sugar beet plants varying in degree of resistance and susceptibility to curly top were inoculated by viruliferous beet leafhoppers (Circulifer tenellus) when plants had two, four, or six true leaves, and maintained in a greenhouse for 6 weeks. When plants were inoculated at the two-leaf stage, all cultivars became severely stunted, with high disease ratings and similar rates of symptom development, regardless of resistance or susceptibility of the cultivar. Plants inoculated at four-and six-leaf stages exhibited increasing separation between resistant and susceptible phenotypes, with highly resistant cultivars performing well with low disease ratings and increased plant weights relative to susceptible cultivars. High-yielding cultivars performed only slightly better than the susceptible control cultivar. Results from greenhouse trials matched those from field trials conducted under heavy curly top pressure. Importantly, low virus concentration was directly correlated with lower disease ratings and higher plant weight, while elevated virus concentrations corresponded to higher disease ratings and lower weights. This demonstrates that a rapid greenhouse assay involving multiple traits can provide a rapid and effective means of selecting cultivars with improved curly top control, and could lead to more rapid incorporation of resistance into high-yielding sugar beet.


1966 ◽  
Vol 46 (2) ◽  
pp. 141-149 ◽  
Author(s):  
Walter J. Kender ◽  
Franklin P. Eggert

A field experiment using various soil management practices showed that the most effective means to increase blueberry plant spread was through the use of a surface mulch. Peat and sawdust were of equal suitability as a mulching material influencing vegetative growth, although sawdust did result in a reduction in the number of flower buds produced when compared with peat. Mulching was associated with a higher soil moisture content than non-mulched plots.Blueberry plants growing in nitrogen-treated plots had an increased flower bud number and rhizome growth in contrast with those growing in unfertilized plots. Nitrogen fertilization was of particular benefit when applied in association with surface organic mulches.Plants growing in an undisturbed soil were more vigorous than in a homogenized or tilled soil. Sawdust was found to be detrimental to the growth of lowbush blueberry plants when incorporated into a homogenized soil.


2021 ◽  
Vol 13 (12) ◽  
pp. 2249
Author(s):  
Sadia Alam Shammi ◽  
Qingmin Meng

Climate change and its impact on agriculture are challenging issues regarding food production and food security. Many researchers have been trying to show the direct and indirect impacts of climate change on agriculture using different methods. In this study, we used linear regression models to assess the impact of climate on crop yield spatially and temporally by managing irrigated and non-irrigated crop fields. The climate data used in this study are Tmax (maximum temperature), Tmean (mean temperature), Tmin (minimum temperature), precipitation, and soybean annual yields, at county scale for Mississippi, USA, from 1980 to 2019. We fit a series of linear models that were evaluated based on statistical measurements of adjusted R-square, Akaike Information Criterion (AIC), and Bayesian Information Criterion (BIC). According to the statistical model evaluation, the 1980–1992 model Y[Tmax,Tmin,Precipitation]92i (BIC = 120.2) for irrigated zones and the 1993–2002 model Y[Tmax,Tmean,Precipitation]02ni (BIC = 1128.9) for non-irrigated zones showed the best fit for the 10-year period of climatic impacts on crop yields. These models showed about 2 to 7% significant negative impact of Tmax increase on the crop yield for irrigated and non-irrigated regions. Besides, the models for different agricultural districts also explained the changes of Tmax, Tmean, Tmin, and precipitation in the irrigated (adjusted R-square: 13–28%) and non-irrigated zones (adjusted R-square: 8–73%). About 2–10% negative impact of Tmax was estimated across different agricultural districts, whereas about −2 to +17% impacts of precipitation were observed for different districts. The modeling of 40-year periods of the whole state of Mississippi estimated a negative impact of Tmax (about 2.7 to 8.34%) but a positive impact of Tmean (+8.9%) on crop yield during the crop growing season, for both irrigated and non-irrigated regions. Overall, we assessed that crop yields were negatively affected (about 2–8%) by the increase of Tmax during the growing season, for both irrigated and non-irrigated zones. Both positive and negative impacts on crop yields were observed for the increases of Tmean, Tmin, and precipitation, respectively, for irrigated and non-irrigated zones. This study showed the pattern and extent of Tmax, Tmean, Tmin, and precipitation and their impacts on soybean yield at local and regional scales. The methods and the models proposed in this study could be helpful to quantify the climate change impacts on crop yields by considering irrigation conditions for different regions and periods.


Author(s):  
Juliana Vantellingen ◽  
Sean C. Thomas

Log landings are areas within managed forests used to process and store felled trees prior to transport. Through their construction and use soil is removed or redistributed, compacted, and organic matter contents may be increased by incorporation of wood fragments. The effects of these changes to soil properties on methane (CH<sub>4</sub>) flux is unclear and unstudied. We quantified CH<sub>4</sub> flux rates from year-old landings in Ontario, Canada, and examined spatial variability and relationships to soil properties within these sites. Landings emitted CH<sub>4</sub> throughout the growing season; the average CH<sub>4</sub> emission rate from log landings was 69.2 ± 12.8 nmol m<sup>-2</sup> s<sup>-1</sup> (26.2 ± 4.8 g CH<sub>4</sub> C m<sup>-2</sup> y<sup>-1</sup>), a rate comparable to CH<sub>4</sub>-emitting wetlands. Emission rates were correlated to soil pH, organic matter content and quantities of buried woody debris. These properties led to strong CH<sub>4</sub> emissions, or “hotspots”, in certain areas of landings, particularly where processing of logs occurred and incorporated woody debris into the soil. At the forest level, emissions from landings were estimated to offset ~12% of CH<sub>4</sub> consumption from soils within the harvest area, although making up only ~0.5% of the harvest area. Management practices to avoid or remediate these emissions should be developed as a priority measure in “climate-smart” forestry.


Pedosphere ◽  
2019 ◽  
Vol 29 (2) ◽  
pp. 235-247 ◽  
Author(s):  
Wiqar AHMAD ◽  
Farmanullah KHAN ◽  
Zahir SHAH ◽  
Muhammad Jamal KHAN

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