Brassicas crop rotation

Indian mustard (Brassica juncea Czern L.), tall fescue (Festuca arundinacae), birds foot trefoil (Lotus corniculatus), and kenaf (Hibiscus cannibinus) have been used to reduce soil Se levels near Los Banos, California. Total Se concentrations in soil depths from 0 to 60 cm were lower in all cropped plots than in the bare plots after four years (Banuelos, 2000). The efficiency of Se lost from the soil after four years for each of the four crop rotations was in the range of 17-60% (Banuelos, 2000). The cropped plots with only tall fescue had 25% lower soil Se concentrations after four... 

Brassicas need firm, moisture-retentive soil they do not thrive in dry conditions. In a crop rotation, this family best follows on from the nitrogen-fixing pea and bean family (see p.242). A green manure crop of winter vetch or clover provides leafy brassicas with all the nitrogen... 

Brassicas may make up a high proportion of the crops you grow, so it is important to have a thorough crop rotation plan to try to avoid clubroot, their most serious disease. Spores can survive in the soil for 20 years in the absence of a host crop. Avoid bringing in the disease on plants and soil. 

In an outdoor crop rotation, they can be included In potato or brassica beds, or given their own section. 

The main reason for this rotation method is to avoid the build-up of pests and diseases, which attack plants that are botanically related. Crop rotation also helps to keep a balance of nutrients in the soil—legumes, for example, release nitrogen into the soil and so are good crops to grow before brassicas, which need high levels of nitrogen. The rotation system also helps to control weeds some crops, such as pumpkins and potatoes, have lots of leafy cover that suppresses weeds others, such as carrots, allow weeds to germinate easily. 

Wide rotations are effective at reducing the risk as well as having a rotation with few if any brassica crops or host weed species. Grow tolerant varieties. No nematicides are currently approved for use in the UK. 

Brassicas Brassicaceae/Cruciferae) Some in this group are quick-growing vegetables, such as radish, salad rocket, and salad mustard. Most, such as broccoli, brussel sprouts, cabbage, calabrese, cauliflower, kale, and turnip, are in the ground for several months, and it is these crops that need to be rotated. 

The crop fits well into a cereal rotation on land that is clean and fertile. The earliest crops are cleared by the end of September and so it is possible to follow with winter wheat. Where club root is a problem, particularly on acid soils, brassicas should be grown no more than one year in four or five with a plaimed liming poUcy before planting. It is possible to grow brassicas continuously on a high pH soil. 

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