Crop diversification for weed management - Ecological Management of Agricultural Weeds - page 336

Figure 7.4 Ground cover produced by cover crops and weeds two months after
seeding in an experiment conducted on the Canterbury Plains,New Zealand.
(Adapted from McLenaghen et al. ,1996.)
may play an important role in weed management, long-term impacts of cover
cropping on weeds remain poorly understood. Multiyear field experiments
comparing weed dynamics in rotations with and without cover crops are
needed to address this issue.Models of weed population dynamics will also be
useful for identifying which weed species may decline and which species may
become more abundant with different cover crop management strategies.
Intercropping
Why farmers plant crops in mixtures
Intercropping is practiced widely where farmers seek (i) the highest
combined yield of two or more crops per unit of land area, or (ii) the smallest
risk of not meeting food or income requirements. Intercropping is particu-
larly important where crop production and food security are challenged by
a limited amount of arable land, and stressful soil, pest, and climatic
conditions.
Intercrop yield performance is most often assessed by calculating a land
equivalent ratio (LER), which indicates the total amount of land that must be
sown in different sole crops to produce the same yields obtained from one