Rotational crop system

Yakle GA, Cruse RM (1984) Effects of fresh and decomposing com plant residue extracts on com seedling development. Soil Sci Soc Am J 48 1143-1146 Young CC, Zhu Thoume LR, Waller GR (1989) Phytotoxic potential of soils and wheat straw in rice rotation cropping systems of subtropical Taiwan. Plant Soil 120 95-101 Yu JQ (2001) Autotoxic potential of cucurbit crops phenomenon, chemicals, mechanisms and means to overcome. J Crop Prod 4 335-348... 

Koocheki, A., Nassir, M., Zare, A. Alimoradi, L. (2002) Weed Dynamics of Conventional and Ecological Cropping Systems in Different Rotations with Wheat. Proceedings of the 14th IFOAM Organic World Congress, Victoria BC, Canada, p. 59. 

Another approach is the utilization of allelopathic rotational crops or companion plants in annual or perennial cropping systems (19). Living rye (Secale cereale L.) and its residues have been shown to provide nearly complete suppression of a variety of agroecosystem weeds (33). Similarly, residues of sorghums, barley, wheat and oats can provide exceptional suppression of certain weed species Q ). Although some progress has been made on identifying the allelochmicals from these plants, much remains to be accomplished. 

Crop rotation is the keystone of organic cropping systems and its importance is emphasized by all organic crop production standards, not only for its role in crop protection, but also for its contribution to soil fertility. Soil fertility may influence the severity of disease infection or offset its effects by accelerating the build-up of yield before the disease takes its toll. This aspect is considered further in Section 18.4.4. 

Results after the first and second rotation. The systems varied in fertiliser (synthetic or organic), winter cover crop and irrigation frequency (Cunapala and Scow 1998). 

Olesen, J.E. 1999. Perspectives for research on cropping systems In Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S. and Kbpke, U. (eds) Designing and Testing Crop Rotations for Organic Farming. DARCOF, Tjele. pp. 11-20. 

Atrazine remains the standard herbicide for making the transition from wheat to sorghum or corn in Great Plains cropping systems. Even where more intensified crop rotations have been developed, they are built around winter wheat followed by ecofallow sorghum or com. The success of atrazine is due to its persistence as a soil-applied herbicide, to the broad spectrum of weeds controlled, to its low cost per acre, and to its safety on sorghum and com. In the Great Plains, repeated burndown of weeds in fallow with nonresidual herbicides is not a viable alternative to the role that atrazine plays. 

Triazine herbicides are particularly well suited for conservation tillage because they provide foliar and residual control of a broad spectrum of weeds. Atrazine, simazine, and metribuzin are used in com, atrazine and propazine in sorghum, metribuzin in soybean, and simazine reduces tillage required for weed control in many perennial and tree crops. Atrazine is also used extensively in chemical fallow cropping systems in rotations involving corn, sorghum, and wheat. Cyanazine was also used extensively in corn and cotton until 2002. 

Janke, R. and S. Peters (1989). Cover crops, crop rotation, and weed control in sustainable cropping systems. Proceedings - Penn-Jersey Tillage Conference 1989, Bethlehem, PA. 

Tuskan, G.A. Walsh, M.E. Short-rotation woody crop systems, atmospheric carbon dioxide and carbon management A US case study. For. Chron. 2001, 77,259-264. 

No use of various cropping system approaches (crop rotation, inter cropping, mixed cropping, improved fallow systems, hedge systems)... 

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