No-Tillage and High-Density Planting for Tahiti Acid Lime Grafted Onto Flying Dragon Trifoliate Orange

Abstract

The management of soil cover plants (intercropping) in orchards can contribute to increase productivity of citrus trees. Thus, the present research aimed to evaluate different planting systems for Tahiti acid lime grafted onto Flying Dragon trifoliate orange, a dwarfing rootstock, at high planting density (1,157 trees ha −1). The study was set up in four tillage systems, using Urochloa ruziziensis as an intercrop species in the orchard, and conducted for 5 years: no-tillage (NT), no-tillage and no-herbicide (NT-NH), minimum tillage (MT) and conventional tillage (CT; without intercropping). Dry matter (DM) production of biomass in the row and interrow of the orchard was evaluated yearly, as well as weed density, soil physical and chemical characteristics, plant water and nutritional status, and fruit yield of trees. Greater deposition of DM of biomass was observed in the row of citrus planting for treatments NT and NT-NH compared to CT and MT treatments, which led to reduced undesirable weed populations. The NT treatment also provided increases of 79% in potassium (K) nutrient concentrations in the leaves of trees and 60% in exchangeable K in the soil surface layer, in the first 2 years evaluated. The maintenance of the Urochloa ruziziensis mulch in the NT system also provided higher soil volumetric moisture content and consequently lower soil resistance penetration and water stress on trees, evidenced by the predawn plant leaf water potential (<1 MPa). Moreover, the NT treatment provided an average increase of 56% of fruit yield from trees compared to the CT treatment during three harvests. This long-term study demonstrated the contribution of the no-tillage system using a favorable cover crop to increase the yield of Tahiti acid lime fruits and maintain the soil quality most required for the sustainability of citrus production.

The impacts of ecological mowing combined with conventional mechanical or herbicide management on weeds in orange orchards

“…L.], radish [Raphanus sativus L.]) and natural vegetation, and reported results ranged from 0.5 to 7.8 t ha À1 for the ECO treatments (up to 8.8 times greater than that of the CONV treatment), with the lower values related to the natural vegetation. Although, it is noteworthy that the amount of biomass deposited by ECO is only achieved by the high levels of biomass produced by U. ruziziensis, which has already been reported for other citrus species, such as on Tahiti lime orchards in standard planting spacing (up to 8.7 t ha À1 per year) (Martinelli et al, 2017) and high-density planting systems (up to 7.4 t ha À1 per year) (Azevedo et al, 2020). In addition, this is a perennial Urochloa species, with the advantage of being planted only once at a lower cost than annual cover crops.…”

Physical quality of sandy soils under orange orchards in Southern Brazil

“…Urochloa decumbens)] and Palisadegrass)} in Brazilian tropical soils (Oliveira et al, 2016;Silva et al, 2021). Thus, strategies to reduce the intensity of soil tillage during the establishment of orchards, maintenance of living and dead vegetation cover in the interrow and better distribution of machinery traffic in orchard interrows (Neves et al, 2010;Azevedo et al, 2020) contribute to physical and water improvements through conventional tillage only in the orange tree planting lines to establishment of orchards in pastures, because of the effects of grasses in maintaining the physical quality of the soil (Hondebrink et al, 2017).…”

Implication of Urochloa spp. Intercropping and Conservation Agriculture on Soil Microbiological Quality and Yield of Tahiti Acid Lime in Long Term Orchard Experiment

“…The treatments were distributed as follows: the plot represented the two species of tropical Poaceae, U. ruziziensis (RUZ), and U. decumbens (DEC). In the subplots we represented the management of these Urochloa spp., either via a conventional mower (CONV), which cuts the biomass and allows the residue to remain in the inter-row (between citrus rows) area ( Figure 1A), or with an ecological mower (ECO), which cuts in the inter-row area and launches the resulting biomass into the intra-row area [14] ( Figure 1B). The sub-subplots were represented by either the use of glyphosate (H) or the absence of glyphosate (NH), with 3 L ha −1 ; 1080 g ae ha −1 , on the intra-row.…”

“…The use of the herbicide glyphosate in citrus rows is a common practice in citrus orchards [13,14]. However, despite its biodegradation in soil, its effect on the shikimic acid pathway can cause disturbances in the cellular metabolism of bacteria, fungi, plants, and other organisms [15], and can harm the composition of the soil microbial community [16].…”

“…such as U. decumbens and U. ruziziensis. These are sown at the beginning of the planting in the citrus inter-rows and are managed throughout the cycle of the main crop; after cutting, the biomass is deposited in the intra-rows, by the lateral "ecological" type of mower [14]. Benefits of this system were found in the cultivation of Pera sweet orange, in which green manure of the winter biomass deposited in the intra-row resulted in increased yields [22].…”