Corn Yield Intercropped With White Clover as Living Mulch

Brazil southern region edaphoclimatic conditions allow farmers to grow perennial winter legumes. However, at summer, a seasonality occurs in the production of these species allowing the grown of annual crops such as corn. In this way, interference between white clover (Trifolium repens L.) living mulch and corn crop (Zea mays L.) was studied using a clover sward established after one and two growing season in relation to the usual system of corn grown over black oat straw aiming to study the relationships occurring in this intercrop, such as white clover herbicide suppression, competition and its nitrogen effects on corn yield as well as its potential to became perennial after corn harvest. White clover suppression management was established in the main plots and corn nitrogen fertilization (0, 60, 120, 180 kg ha-1) was performed in the subplots (4.2 × 8 m) in a randomized block design with four replications. White clover suppression managements were: (i) partial suppression achieved by mowing the plots at the corn seeding day; (ii) partial suppression achieved by mowing plus chemically broadcast application of 2.4-D; (iii) partial suppression achieved by a chemically broadcast application of glyphosate. Corn grain yields ranged from 3.0 to 12.2 Mg ha-1. Nitrogen input and herbicide management are important elements to reduce white clover competition and increase corn yield. It is possible to manage white clover as living mulch in corn with its full recovery after corn harvest without replanting. Clover with 1 cycle is easier suppressed than perennial clover sward and can be handled in intercropping with corn without affecting grain yield, with ability to resume growth in the next growing season.