scholarly journals Maize Growth and Grain Yield Responses to a Micronized Humic Product Across Soil Types and Annual Weather Patterns in Central Iowa, United States

2021 ◽  
Vol 12 ◽  
Author(s):  
Daniel C. Olk ◽  
Dana L. Dinnes ◽  
J. Rene Scoresby ◽  
Jerald W. Darlington ◽  
Charles R. Hurburgh ◽  
...  
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Statistical Significance ◽  
Application Rate ◽  
Soil Types ◽  
Nutrient Concentrations ◽  
Spatial And Temporal Variability ◽  
Maize Growth ◽  
Product Application ◽  
Humic Products

Despite growing interest in humic products as crop amendments, very few field evaluations have considered environmental factors of humic product efficacy. We determined the spatial and temporal variability in the efficacy of a micronized humic product on maize (Zea mays L.) growth and grain yield in two rainfed fields supporting a maize−soybean [Glycine max (L.) Merr.] rotation in 2012–2014, and 2016 in central Iowa, U.S. Crop management in both fields otherwise followed conventional farmer practices. In two dry growing seasons, mechanized combine measurements of grain yield increased significantly (P < 0.10) with humic product application on an eroded hilltop soil, amounting for two application rates to 930 and 1,600 kg ha–1 (11 and 19% of the control grain yield) in 2012, the droughtiest season, and 700 kg ha–1 (7% of the control) for the higher application rate in the somewhat droughty 2013 season. On a fertile side slope soil in the 2012 field, though, only a faint numeric response occurred in 2012, while on a toe slope soil the sole significant increase was in 2012, 870 kg ha–1 (14% increase above the control) for one application rate. With favorable rainfall in 2014 and 2016, significant grain yield increases with product application were small in the upland soil of 2014 and absent in 2016. Yield components analysis on 1-m row lengths of hand-collected samples attributed these yield boosts primarily to increased ear length, especially of the shorter ears. Combine grain yields, yield components, and total leaf area all demonstrated numerically slightly greater values for humic product treatments compared to the control in the vast majority of comparisons across years and soil types, with better distinction in the upland transects. Statistical significance, though, was reached only in the droughtier settings. The humic product had no consistent effects on nutrient concentrations of the grain, stover, or young leaves. Grain quality parameters showed a slight shift from protein to carbohydrates in the droughtier settings. Fifteen soil properties showed no response to the humic product. This humic product demonstrated the capability to improve maize growth in rainfed conditions in a high-yielding region, and its efficacy varied predictably with environmental conditions. This finding provides one potential explanation for inconsistent reports elsewhere of crop responses to humic products.

scholarly journals Maize Growth Responses to a Humic Product in Iowa Production Fields: An Extensive Approach

2022 ◽  
Vol 12 ◽  
Author(s):  
Daniel C. Olk ◽  
Dana L. Dinnes ◽  
Chad R. Callaway
Keyword(s):  
Yield Component ◽  
Grain Weight ◽  
Nutrient Concentrations ◽  
Growth Responses ◽  
Total Leaf Area ◽  
Maize Growth ◽  
Growing Seasons ◽  
Field Efficacy ◽  
Product Application ◽  
Maize Grain

Field evaluations of commercial humic products have seldom involved replication across location or year. To evaluate the consistency of humic product efficacy in field conditions, we determined the effects of a humic product on maize (Zea mays L.) growth in high-yielding Midwestern (US) fields through the following two extensive approaches: (i) replicated strip plots in five site—year combinations from 2010 to 2013; and (ii) demonstration strips in 30–35 production fields annually from 2009 to 2011 that covered major areas of Iowa. Mechanized combine measurements of grain yield showed increases of 0.2–0.4 Mg ha–1 (1–4%) with humic product application for all five site—year combinations of the replicated strip plots. Six of 10 humic treatments within the fields responded positively (P < 0.07), and the positive responses of two more treatments approached significance at the benchmark of P = 0.10. In the demonstration strips, maize grain weight in hand-collected samples increased significantly (P < 0.004) with humic product application in each of the three growing seasons, and across all the three seasons by 6.5% (P < 0.001). Grain weight increased numerically for 76 of the 98 demonstration strips. Yield component analysis for both the replicated strip plots and the demonstration strips attributed the yield boosts largely to increased ear length, especially of the shorter ears. Humic product application caused significantly (P < 0.10) greater total leaf area in all eight field treatments at three site—year combinations. Humic product application did not consistently affect nutrient concentrations of the grain or stover or any measured soil property. These results represent among the widest geographic evaluations published on field efficacy of a humic product. They demonstrate the capability of a humic product to improve maize growth in high-yielding conditions.

Response of Corn Grain Yield to Spatial and Temporal Variability in Emergence

Crop Science ◽  
2004 ◽  
Vol 44 (3) ◽  
pp. 847 ◽  
Author(s):  
Weidong Liu ◽  
Matthijs Tollenaar ◽  
Greg Stewart ◽  
William Deen
Keyword(s):  
Grain Yield ◽  
Temporal Variability ◽  
Spatial And Temporal Variability ◽  
Corn Grain ◽  
Corn Grain Yield

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

scholarly journals Epistasis for Three Grain Yield Components in Rice (Oryxa sativa L.)

Genetics ◽  
1997 ◽  
Vol 145 (2) ◽  
pp. 453-465 ◽  
Author(s):  
Zhikang Li ◽  
Shannon R M Pinson ◽  
William D Park ◽  
Andrew H Paterson ◽  
James W Stansel
Keyword(s):  
Grain Yield ◽  
Complex Traits ◽  
Yield Components ◽  
Genetic Basis ◽  
Kernel Weight ◽  
Progeny Testing ◽  
Grain Yield Components ◽  
Main Effects ◽  
Grain Number Per Panicle

The genetic basis for three grain yield components of rice, 1000 kernel weight (KW), grain number per panicle (GN), and grain weight per panicle (GWP), was investigated using restriction fragment length polymorphism markers and F4 progeny testing from a cross between rice subspecies japonica (cultivar Lemont from USA) and indica (cv. Teqing from China). Following identification of 19 QTL affecting these traits, we investigated the role of epistasis in genetic control of these phenotypes. Among 63 markers distributed throughout the genome that appeared to be involved in 79 highly significant (P < 0.001) interactions, most (46 or 73%) did not appear to have “main” effects on the relevant traits, but influenced the trait(s) predominantly through interactions. These results indicate that epistasis is an important genetic basis for complex traits such as yield components, especially traits of low heritability such as GN and GWP. The identification of epistatic loci is an important step toward resolution of discrepancies between quantitative trait loci mapping and classical genetic dogma, contributes to better understanding of the persistence of quantitative genetic variation in populations, and impels reconsideration of optimal mapping methodology and marker-assisted breeding strategies for improvement of complex traits.

Seagrass characterization on the southern Pacific coast of Costa Rica: history, vegetation, and environment

2020 ◽  
Vol 63 (5) ◽  
pp. 429-438
Author(s):  
Jimena Samper-Villarreal ◽  
Jorge Cortés
Keyword(s):  
Costa Rica ◽  
Pacific Coast ◽  
Management Strategies ◽  
Shoot Density ◽  
Nutrient Concentrations ◽  
Seagrass Habitat ◽  
Spatial And Temporal Variability ◽  
Seagrass Species ◽  
Seagrass Biomass ◽  
Herbarium Collections

AbstractSeagrass conservation and management requires scientific understanding of spatial and temporal variability, information that is currently limited for the Eastern Tropical Pacific (ETP). Here, we analysed seagrass presence based on previous reports, herbarium collections and stakeholder knowledge, combined with field characterization in Golfo Dulce, southern Pacific coast of Costa Rica. Seagrasses were found at multiple locations along a narrow border close to shore and in up to 6 m depth within Golfo Dulce, dating back to 1969. Two seagrass species were found, Halophila baillonii and Halodule beaudettei. Seagrass biomass values for Golfo Dulce (12.0 ± 8.5 g DW m−2) were lower and water nutrient concentrations were higher than previously reported in the gulf. Shoot density (1513 ± 767 shoots m−2) was similar to previous reports. Stable isotope values in seagrass were −11.3 ± 1.0‰ δ13C and 1.2 ± 0.9‰ δ15N; while those in sediments were −26.1 ± 1.3 and 2.5 ± 0.9‰. In Golfo Dulce, isotopic values of both seagrass species do not overlap with other known primary producers. Management strategies should aim to minimize known seagrass stressors, protect potential seagrass habitat, and take into account the dynamic life strategies of the two seagrass species found.

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