Ridge planting for row crops on a poorly drained soil. 2. Anhydrous ammonia and UAN [urea-ammonium nitrate] management for maize following soybean

abonado fraccionado alomado ammonia ammoniac billonnage clay soils drainage drenaje fertilisation fertilizer application glycine max rendement rendimiento ridging rotation culturale rotational cropping silty soils sol argileux sol limoneux split dressings suelo arcilloso suelo limoso yields zea mays