Root distribution and soil management in a papaya cultivation in the Coastal Tablelands

Abstract

The objective of this work was to compare the root distribution and fruit yield of papaya in two crop production systems, in an Ultisol of the Coastal Tablelands, in the state of Bahia, Brazil. In the first production system commonly used by producers, bare soil, fertigation, and ridges were used; and, in the second system, subsoiling, planting in furrows with various cover plants, and irrigation were used. Ridges isolate roots from water excess and soil fungi; however, they require many mechanical practices, compact the soil, and degrade the area, resulting in the necessity of fallow and, eventually, of crop migration. Sampled roots were soil-free by sieve-washing, then they were scanned, and their length and diameter were measured. The T1 (native vegetation), T2 (leguminous plants), T3 (grass), and T4 (leguminous plant and grass) treatments – without using ridges and irrigated – showed lower root density and fruit yield than the T5 (control) treatment without cover vegetation, with ridges and fertigation. Fertigation increases root density, but concentrates them under the drippers. Cover crops outweigh native vegetation as to root density; however, they are similar as to productivity.