Crop rotation practice

The document sections referring to soil fertility management ( 205.203) and crop rotation practices ( 205.205) run along the same lines as those in the EU s standards. Neither section displays a particular awareness of salinity. 

Nonchemical or traditional practices, such as weed seed removal, optimal crop seeding rates, crop selection, enhanced crop competitiveness, crop rotation, and mechanical weed control are all important components of an effective weed management program (458,459). In the context of modern intensive chemical herbicide appHcation, nonchemical practices may even represent an innovative approach to weed management and should receive careful consideration. 

Crop Rotations and Diversification. For thousands of years farmers have known that planting their crops in a new location about every 2 years helped reduce Insect, disease, and weed problems. Indeed, crop rotations are effective in reducing many pest problems and are often highly cost effective (15, 16). Unfortunately for many crops, the trend has been toward abandonment of rotations and increased monocultures. Where rotations are not practiced, certain pests tend to multiply as the crops are cultured on the same land year after year (23). As a result, the density of pest populations increases to levels that necessitate heavy pesticide applications. 

A practice somewhat related to crop rotation is crop diversification or polyculture (36). This approach involves planting selected combinations of crops, like corn and beans. 

Pesticides used on crops grown on the test site in previous seasons may also have an impact on the outcome of a field residue trial. Carryover of prior pesticide applications could contaminate samples in a new trial, complicate the growth of the crop in a trial, or cause interference with procedures in the analytical laboratory. For this reason, an accurate history of what has transpired at the potential test site must be obtained before the trial is actually installed. The protocol should identify any chemicals of concern. If questions arise when the history is obtained, they should be reviewed with the Study Director prior to proceeding with the test site. In most annual crop trials, this will not be a significant issue owing to crop rotations in the normal production practices, because the use of short residual pesticides and different chemical classes is often required for each respective crop in the rotation. However, in many perennial crops (tree, vines, alfalfa, etc.) and monoculture row crops (cotton, sugarcane, etc.), the crop pesticide history will play a significant role in trial site selection. 

Describe (where possible) the production system components (e.g. crop or livestock health management practices, soil fertilisation methods, crop rotation designs, livestock feeding and husbandry regimes, crop varieties/livestock breeds used) responsible for differences in food quality and safety between production systems ... 

One of the most important methods of reducing Fusarium infection risk by minimizing inoculum levels is to establish diversified crop rotations which avoid growing maize and cereals before cereals. Since maize as a pre-crop for cereals (especially wheat) is rarely used in organic systems, this risk is applied mainly to conventional farming systems where this practice has increased over the last 20 years. 

Chan KY, Heenan DP (1999) Microbial-induced soil aggregate stability under different crop rotations. Biol Fertil Soils 30 29-32 Chantigny MH (2003) Dissolved and water-extractable organic matter in soils a review on the influence of land use and management practices. Geoderma 113 357-380... 

Peters RD, Sturz AV, Carter MA, Sanderson JB (2003) Developing disease-suppressive soils through crop rotation and tillage management practices. Soil Till Res 72 181-192 Pfiffner L, Luka H (2003) Effects of low-input farming systems on carabids and epigeal spiders - a paired farm approach. Basic Appl Ecol 4 117-127 Pimentel D, Harvey C, Resosudarmo P, Sinclair K, Kurz D, McNair M, Crist S, Shpritz L, Fitton L, Saffouri R, Blair R (1995) Environmental and economic costs of soil erosion and conservation benefits. Science 267 1117-1123... 

Low soil fertility No fallow practices, no crop rotation, no manure application, over-plowing... 

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