be killed too rapidly, so that broadleaf weeds invaded the corn. This study suggested that the timing and dosage of herbicide should be carefully considered. Living mulches were tested in a no-till corn-production systems with two methods for establishing grass and legume living mulches (grass and legume) between corn rows. In 1985, there was no difference between drilling and broadcasting seeds by hand in that study. However in 1986, drilling resulted in higher populations (97 plants m-2) than broadcasting (64 plants m-2), likely because of precipitation levels. Precipitation should be considered because farmers have no control over it. Beard (1973) recommended chewing fescue (red fescue) (Festuca rubra var "commutata" var "shadow FESRU") as a good living mulch because it adapts to the shady conditions under corn and soybean. This grass is also well adapted to dry and poor soils. Plant nutrition Legume cover crops have important positive effects on the nutrient cycling of tree crops. Leguminous living mulches work in three ways: Fixing the atmospheric N2 that is important for the main crop, Recycling soil nutrients, and Enhancing soil nutrient availability for the main crop. Lehmann et al. (2000) measured the above ground biomass accumulation of Pueraria phaseoloides, which is a living mulch used in tropical tree crops. They found that Pueraria accumulated 8.8 metric ton of dm (dry matter) ha-1 as compared with 4.4 t dm ha−1 for Theobroma grandiflorum, and 1.4 t dm ha-1 for Bactris gasipaes. These latter two species are native cultivated species from the Amazon. Control of erosion Vegetative cover as living mulches protect soil against wind and water erosion. Plants should form a mantle or thick mulch that protect soil from detachment. Living mulches intercept raindrops and reduce runoff. The protection that such vegetation provides against wind is influenced mainly by the amount of biomass that covers the ground (differs with each spp), plant geometry and row orientation. In one experiment, water runoff and soil loss on a 14% slope was compared for rototilled (RT), no-till with corn stover mulch (NT-CSM), no-till in CSM+ birdsfoot trefoil living mulch (NT-BFT) and no till in CSM and crownvetch living mulch (NT-CV). The results indicated that the water runoff was 6,350 L ha-1 for NT-BFT, 6,350 L ha-1 NT-CSM, 5,925 L ha-1 for NT-CV, and 145,000 L ha-1 for RT. The soil loss for the RT was 14.22 t ha-1 while with the other treatments it was