نتایج جستجو برای: crop year

تعداد نتایج: 655132  

C. Leifert J. Cooper M. Eyre N. Critchley R. Sadrabadi Haghighi

We investigated the effects of organic and conventional pest and fertility management on weed cover and the seed bank community in an organic rotation. The study was conducted during the 4th and 5th years of an organic rotation on part of a long term organic-conventional comparison trial. Results showed that although crop type (potato vs. cabbage) in a single year significantly affected wee...

Journal: :حفاظت گیاهان 0
مهدی مجاب مجتبی حسینی سیدوحید اسلامی

introduction: elimination or reduction of tillage in conservation agricultural systems has led to wide variations in germination, emergence, and growth of weeds and has caused variations in the density and diversity of weeds under such systems. maintaining crop residues on the soil surface has many potential benefits in agricultural production systems; such as reducing water and wind erosions, ...

Journal: :Applied and environmental microbiology 1978
R F Vesonder A Ciegler R F Rogers K A Burbridge R J Bothast A H Jensen

Fifty-two preharvest corn samples were collected in mid-October 1977 from 26 farms in a four-county area of northwest Ohio. Vomitoxin ranging from 0.5 to 10 microgram/g was found in 24 of the samples. Analysis for vomitoxin was by gas-liquid chromatography. Preceding harvest in northwest Ohio, unusual wet conditions prevailed, making it favorable for Fusarium growth. Gibberella zeae-infected ke...

Journal: :Decision Support Systems 2003
John H. Gerdes

Publicly owned companies, their officers and major investors are required to file regular disclosures with the Securities and Exchange Commission (SEC). To improve accessibility to these public documents, the SEC began developed the EDGAR (Electronic Data Gathering, Analysis and Retrieval) electronic disclosure system. This system provides ready, free access to all electronic filings made since...

2002
R. C. Le Bayon S. Moreau C. Gascuel-Odoux F. Binet

Investigations were conducted on both the annual patterns of earthworm casting activity and Ž . the annual variations in soil and phosphorus P transfers by water runoff, under a temperate maize crop, to determine whether there is any time synchronism over the year between these processes that could increase risk of soil erosion. Cast dynamics were measured at 15-day intervals for 1 year. Phosph...

2012
Bharat M. Shrestha Richard L. Raddatz Raymond L. Desjardins Devon E. Worth

Summerfallow is cropland that is purposely kept out of production during a growing season to conserve soil moisture. On the Canadian Prairies, a trend to continuous cropping with a reduction in summerfallow began after the summerfallow area peaked in 1976. This study examined the impact of this land-use change on convective available potential energy (CAPE), a necessary but not sufficient condi...

2012
C L MOHLER C DYKEMAN E B NELSON

Because tillage promotes the germination of many weed species and freshly killed plant material favours the growth of microbial pathogens, we hypothesised that the incorporation of green crop residue should temporarily reduce weed seedling emergence relative to unamended soil. Soil with field-incorporated green crop residue was compared with non-amended soil in glasshouse experiments by sowing ...

2013
T M Osborne T R Wheeler

Low variability of crop production from year to year is desirable for many reasons, including reduced income risk and stability of supplies. Therefore, it is important to understand the nature of yield variability, whether it is changing through time, and how it varies between crops and regions. Previous studies have shown that national crop yield variability has changed in the past, with the d...

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