Planting soybean on the optimum date produces maximum yield and profit without increasing production costs. Unfortunately, the optimum planting date is hard to indentify, because it varies from year to year, depending on the weather and how much it rains and when it rains.
"Planting date has been a favorite topic of researchers ever since soybean was introduced into the United States, so there is a large database of experiments in the literature. A combined analysis of this database will provide a clearer picture of the average response than any single experiment," explains Dr. Dennis Egli, University of Kentucky, Lexington.
Dr. Egli and colleagues at the University of Kentucky analyzed the combined results of planting date experiments and published their findings in the March-April 2009 issue of the Agronomy Journal.
The scientists analyzed combined results of planting date experiments from the Midwest (NE, ND, IA, IL, IN, and OH), the Upper South (AR, KY, MO, and TN), and the Deep South (AL, FL, GA, LA, MS, and SC). Planting dates varied from mid-April (early April in the Deep South) to July. The experiments included several varieties and several row spacings, but none were irrigated.
In spite of the differences in environmental conditions and varieties from the Midwest to the Deep South, the response of yield to planting date was remarkably consistent across the three regions. Average yield did not change as planting was delayed from mid-April until late May or early June. Thus, there was no evidence that April plantings produced higher yields in any of the three regions. Early April plantings were included in the Deep South and average yields decreased for these ultra-early plantings.
A previous study published in the Agronomy Journal [Vol. 101:131-139 (2009)] concluded that April and early May plantings in Indiana consistently produced the highest yield. But our results, based on the combined analysis of 28 experiments, show no significant advantage for such early plantings from the Midwest to the Deep South.
While the results of this analysis show no consistent yield advantage for planting early, there was also no consistent yield loss (except for ultra-early plantings in the Deep South) associated with early plantings.
"If the soil is ready for planting in April, producers should feel free to plant, but they shouldn’t expect higher yield," advises Egli.
Planting into cold, wet soils, however, can reduce seedling emergence and stand, which may require replanting to avoid yield loss. Unacceptable stands may be more common if seeding rates are reduced to the minimum to reduce seed costs.
Average yield declined rapidly when planting was delayed after 30 May in the Midwest, 7 June in the Upper South, and 27 May in the Deep South at rates ranging from 0.7 (Midwest) to 1.1 (Upper South) and 1.2 ( Deep South) percentage points per day. At these rates, delays of just 2 weeks will reduce yields by approximately 10 to 20%.
There may be no particular advantage for early planting, but there was a clear disadvantage for planting late, after the critical date in late May or early June. Soybean producers can maximize their yield and profits by making sure planting is completed before the critical date.
A peer-reviewed international journal of agriculture and natural resource sciences, Agronomy Journal is published six times a year by the American Society of Agronomy, with articles relating to original research in soil science, crop science, agroclimatology and agronomic modeling, production agriculture, and software.
The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.
Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University
New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Life Sciences
08.12.2016 | Physics and Astronomy
08.12.2016 | Materials Sciences