Root spatial distribution in coffee plants of different ages under conservation management system

Abstract

Root system growth and soil structure are interdependent and the threshold of separation between both of them is complex. However, by the evaluation of soil pore space, it is possible to characterize the root system growth environment. The aim of this study was to evaluate the effect of conservation management system over time on pore distribution and on root system development of coffee plantation in Cerrado Oxisol, located in the state of Minas Gerais, Brazil. Two coffee plantation areas were sampled (3 or 6 years old). Trenches were dug lengthwise along the planting row to expose the root system and the vertical profiles were divided into 0.05 × 0.05 m grid cells (0.70 × 1.50 m grid), totaling 420 sample sites. Digital images were taken and using the computer software Safira, it was measured layers along the soil profile, which was spaced 0.10 m apart. Disturbed and undisturbed soil cores the length, the surface area and the volume of the root system were sampled at 0.20 to 0.34, 0.80 to 0.94, and 1.50 to 1.64 m depths layers, in order to determine particle size, total porosity, and pore size distribution. The 3-years coffee stand had the greatest volume of macropores and the largest number of absorbent roots, besides a noticeable root system growth below 1 m depth. The 6-years old coffee stand presented pores reconfiguration due to increase in the intermediate-sized pores and to the uniform root distribution in both horizontal and vertical directions up to 0.9 m depth.

Soil Management and Water-Use Efficiency in Brazilian Coffee Crops

“…Silva et al [8] found a significant volume of inter-aggregate pores (macropores) after 3 years of coffee cultivation in Latosols, confirming the benefits of the management system using deep preparation associated with surface gypsum application. In the layer between 0.20-0.40 m of the soil, even after 5 years of cultivation, Silva [20] also found that soil management favored the expressive increase of pore volume of classes 9.0-2.9, 2.9-0.6 and 0.6-0.2 μm (mesopores), which is relevant since a good portion of the water retained in the soil will be available to the plants.…”

“…Particularly in Latosols under this management system, it was observed that in the absence of chemical and physical limitations of the soil the coffee root system reached depths greater than 1 m at 3 years of age (Figure 3), which is of fundamental importance to ensure crop survival in periods of edaphic drought [8].…”

“…With the advancement of knowledge and technologies, it has been found that coffee roots can reach depths well above 1 m when in the absence of physical limitations and when adequate chemical conditions [6][7][8], such as sufficient calcium, phosphorus and boron contents, are provided [9].…”

“…The ability of gypsum to increase Ca 2+ levels in the deepest soil layers is important for the proper development of the crop root system, especially because Ca 2+ is the main component of the cell wall, being responsible for root elongation and growth [6][7][8].…”

“…Coffee is mostly grown intercropped with Brachiaria between rows [10]. This grass is periodically mowed and its residues remain in the coffee line, representing continuous input of organic matter to the soil [8]. Thus, SOM contributes to Soil Management and Water-Use Efficiency in Brazilian Coffee Crops DOI: http://dx.doi.org /10.5772/intechopen.89558 increased CEC and improved nutrient utilization efficiency by providing a significant number of binding sites for essential elements present in the soil [14].…”