Coffee Rows Research Articles

Spatial trajectories of coffee harvesting in large-scale plantations: Ecological and management drivers and implications

CONTEXTCoffee is produced under different management systems and scales of production categorized as Syndromes of Production. The “Capitalist Syndrome” is characterized by large-scale and high-density planting farms that may promote the development of plant pathogens like coffee leaf rust (CLR). Harvesting dynamics are also affected by the syndrome of production and generate spatial trajectories that could contribute to the dispersal of pathogens across and within plantations. However, these spatial trajectories have not yet been described, nor their relationship with the syndrome of production, and even less its potential ecological implications for pathogen dispersal. OBJECTIVEDescribe and analyze the daily spatial movement of coffee harvesters in two large-scale capitalist plantations, an organic and a conventional plantation, and systematize the drivers that might explain the differences in the spatial trajectories. METHODSUsing State-Space Models, we recorded and analyzed the spatial movements of harvesters. We then constructed a driver tree for harvest dynamics, which incorporated qualitative variables related to the environment, coffee biology, and management aspects reported by the harvesters or in previous studies. RESULTS AND CONCLUSIONSThe model differentiated two kinds of movements: 1) when trees have berries, harvesters remain in the coffee rows or areas nearby (Collect state; 94–98 % of the steps); 2) when not, harvesters make longer steps within the harvesting location or move to another area (Search state; 2–6 % of the steps). In the organic plantation, the Search state had a longer-tailed step-length distribution than in the conventional plantation, resulting in a significantly larger visited area per worker (p < 0.05). This might be directly related to the lower interplant ripening percentage or smaller harvesting locations (“pantes”) per number of harvesters. The number of harvested trees might be affected by the fruit load or the coffee variety, among others. Harvesting movements that explore a larger area, either by visiting more plants or by changing locations on the same day, could create more foci of CLR infection across the plantation. SIGNIFICANCEThese results constitute an initial analysis of harvesting trajectories and highlight practices that can reduce the potential impact of human dispersal of pathogens, like shorter harvesting trajectories by working fewer hours a day or avoiding harvesting at the end of the maturation season when few trees have berries and harvesters have to travel medium to long distances. This calls for organic coffee management that could prevent diseases and guarantee just and safe conditions for workers.

Intercropped Soybean Plant Population in a Coffee Plantation and Its Effects on Agronomic Parameters and Geospatial Information

Coffee farming has high land use value, which can result in economic losses without proper land use planning. Intercropping has improved coffee production by providing an alternative income source to producers, especially in the crop formation phase. The objective of this study was to evaluate productivity, growth, and geospatial data in different soybean plant populations intercropped with coffee. The experiment was conducted at the Federal University of Uberlândia, in Monte Carmelo, Minas Gerais, Brazil. It had an experimental randomized block design with five treatments: the control (no soybeans); 80 thousand plants ha−1; 160 thousand plants ha−1; 240 thousand plants ha−1; and 320 thousand plants ha−1. Productive and vegetative characteristics of coffee and soybeans were evaluated, as well as the NDVI and GNDI vegetation indices. The mass of 1000 grains of soybean reached its peak (178.96 g) with a population of 222 thousand plants of soybean ha−1. The maximum soybean productivity of 102.78 bags ha−1 was obtained in the population of 185 thousand plants soybean ha−1. An increasing population of 240–320 thousand plants ha−1 soybean between coffee rows reduced soybean yield due to reduced light, causing plant lodging. The biometric parameters of the coffee trees did not change, which was evidenced by high normalized and green normalized difference vegetation indices (NDVI and GNDVI, respectively). Therefore, it is concluded that the use of soybeans between the coffee trees does not affect the vegetative and productive parameters of the coffee tree, making the use of the intercrop viable.

Evaluación agronómica de quinua intercalada con café a una altitud de 1.800 msnm

Quinoa (Chenopodium quinoa) exhibits great potential for adaptation to various agroecological conditions, making it a diversification option for different production systems. In this regard, the objective of this study was to evaluate and compare the agronomic characteristics of different progenies intercropped with coffee (Coffea arabica) cultivation under Popayan (Colombia) conditions, in order to determine their adaptation potential in coffee regions of Colombia. The research was conducted at the Experimental Farm "La Prosperidad", located in the municipality of Popayan, Colombia, at an altitude of 1,800 m. Ten genotypes were evaluated: five selected from BRS Syetetuba (Brazil), three from Colombia (San José, Aurora, and Blanca Dulce de Jericó), and two from Ecuador (Piartal and Tunkahuan). The planting was done between the coffee rows in the zoca stage, in an experimental area of 406 m2, following a completely randomized block design with four replications. Characteristics such as plant height, panicle size, central panicle perimeter, weight of 1,000 grains, grain yield, dry mass yield, harvest index, and phenological stages were evaluated. All quinoa materials showed an early cycle with a maximum value of 118 days, with ‘San José’, ‘Aurora’, ‘BCX1’, and ‘BCX4’ standing out with averages below 110 days. Grain yields ranged from 1,120 to 2,900 kg ha-1, with the genotype BCX6 standing out with 2,900 kg ha-1 and ‘Piartal’ with 2,883 kg ha-1. The weight of 1,000 grains averaged 2.62 g, and the harvest index was 27.96%. Meanwhile, the contribution of dry matter to the intercropped system was 7,799.50 kg ha-1. The genotypes showed adaptation potential in the intercropping system with coffee. A high variability of quinoa genotypes was observed, which is an interesting characteristic for specific selection processes in diversified production arrangements.

Agronomic performance and productivity of Arabica coffee intercropped with timber species

The insertion of the tree component in coffee production is a strategy from an economic and environmental perspective. Thus, the objective of this study was to evaluate the temporal influence on the agronomic and productive performance of the coffee crop under the interference of different tree species as a function of spacing. The experiment was set in the municipality of Santo Antônio de Amparo-MG, in 2012, and conducted in a randomized block design with four replications. The treatments were: cultivar ‘Catuai Vermelho IAC 99’ in monoculture (3.40 m x 0.65 m) and intercropped with African mahogany, teak and pink cedar, in two spacings (9 x 13.6 m and 18 x 13.6 m), in coffee rows. Three coffee rows were fixed between rows, totaling 13.6 m. The following variables were evaluated: height (m), stem diameter (cm), crown diameter (m), productivity (bags ha-1) and yield (l/sc) for coffee. From the evaluations, there is a significant effect of height, productivity and yield for the coffee crop. The system intercropped with tree species did not influence coffee productivity and yield until the 3rd harvest and, for the 5th harvest, intercropping with mahogany favored productivity, although the accumulated productivity did not show any treatment effect.

Soil enzymatic activity under coffee cultivation with different water regimes associated to liming and intercropped brachiaria

ABSTRACT: This research evaluated the effects of coffee cultivation with two different water regimes associated or not with liming and the presence/absence of brachiaria as intercrop on the activities of the soil enzymes β-glucosidase, arylsulfatase and acid phosphatase. The study was carried out at the experimental farm of Embrapa Cerrados, using the cultivar IAC 144 (Coffea arabica L.), under a clayey dystrophic Cerrado Oxisol. Two water regimes (WR) were considered, WR1 with irrigation shifts throughout the year and WR3 with controlled water stress, for about 70 days, in the dry season. In each water regime, effects of lime application (with/without) and the presence/absence of brachiaria cultivated between the lines of coffee plants were evaluated. The activities of the enzymes β-glucosidase, arylsulfatase and acid phosphatase were evaluated during the rainy and dry seasons. Liming and intercropped brachiaria positively affected the activities of the three enzymes assessed in this study at varying degrees, depending on season and/or the WR. Our findings evidenced that intercropped brachiaria in coffee rows was the factor that most positively impacted soil enzymes activities.

Changes in soil profile hydraulic properties and porosity as affected by deep tillage soil preparation and Brachiaria grass intercropping in a recent coffee plantation on a naturally dense Inceptisol

Soil management operations change soil porosity, affecting water infiltration, redistribution, storage, availability, and uptake by plants. Assessing how soil management may affect pore size distribution and hydraulic conductivity is thus highly relevant for rainfed agriculture coping with water shortage. The aim of this study was to assess the effectiveness of tillage treatments, designed to deepen coffee plants root system, on improving structure and physical-hydric attributes of an Inceptisol with a shallow solum. The study was conducted in an experimental area in the municipality of Nazareno, Minas Gerais State, Brazil. Soil samples were collected 18 months after coffee plantation, at different depths (0, 0.25, 0.35, 0.45, 0.55, 0.66, and 0.75 m) and they were used to determine pore-size distribution, saturated and unsaturated hydraulic conductivity. Samples were also collected in surface crusts or in the 0−0.005 m soil layer for detailed grain size analysis. Field water infiltration was measured at different water tensions. Coffee seedlings were planted in rows furrowed to depths depending on tillage treatment: 0.4 m depth, made by a furrow ridger (FP40); 0.6 m depth, made by a subsoiler coupled to a soil preparer mixing the soil to a depth of 0.6 m (FP60); 0.8 m depth, made by a subsoiler and, after mixing the soil to a depth of 0.6 m, by the soil preparer (FP80). The soil between the planting rows was covered by Brachiaria-grass. Soil sampling and field tests were performed in the coffee plants row mechanically treated, in the Brachiaria-grassed inter-row (IR) lane and in a nearby area under natural vegetation (NC). Treatments effects, either mechanical in the coffee rows (FP40, FP 60 and FP80), or biological in the inter-row lane (IR) were compared to reference (NC), representing soil conditions prior to coffee plantation. The FP60 and FP80 treatments improved water infiltration, storage and hydraulic conductivity in the planting rows to a depth of 0.5 m. A more favorable pore size distribution was obtained following these treatments, which improved the soil physical environment. Conversely, furrowing promoted compaction at each implement working depth due to the pressure applied by the rods in the subsurface soil layers, combined with subsoil moisture condition at the time of operations. Root activity of intercropped Brachiaria-grass (IR) improved soil structure, expressed by a favorable pore-size distribution and a faster hydraulic conductivity in the inter-row lane. Similar effects were obtained with FP 60 and FP80 for the coffee rows, where deep furrowing during soil preparation reduced the natural density of the Inceptisol. Therefore, the management strategies tested allowed root deepening and access to soil moisture stored in deeper layers.

Detection, classification, and mapping of coffee fruits during harvest with computer vision

In this study, an algorithm is implemented with a computer vision model to detect and classify coffee fruits and map the fruits maturation stage during harvest. The main contribution of this study is with respect to the assignment of geographic coordinates to each frame, which enables the mapping of detection summaries across coffee rows. The model used to detect and classify coffee fruits was implemented using the Darknet, an open source framework for neural networks written in C. The coffee fruits detection and classification were performed using the object detection system named YOLOv3-tiny. For this study, 90 videos were recorded at the end of the discharge conveyor of a coffee harvester during the 2020 harvest of arabica coffee (Catuaí 144) at a commercial area in the region of Patos de Minas, in the state of Minas Gerais, Brazil. The model performance peaked around the ~3300th iteration when considering an image input resolution of 800 × 800 pixels. The model presented an mAP of 84%, F1-Score of 82%, precision of 83%, and recall of 82% for the validation set. The average precision for the classes of unripe, ripe, and overripe coffee fruits was 86%, 85%, and 80%, respectively. As the algorithm enabled the detection and classification in videos collected during the harvest, it was possible to map the qualitative attributes regarding the coffee maturation stage along the crop lines. These attribute maps provide managers important spatial information for the application of precision agriculture techniques in crop management. Additionally, this study should incentive future research to customize the deep learning model for certain tasks in agriculture and precision agriculture.

Study of Intercropping System and In Situ Organic Matter Application on Coffee Agroforestry at Citarum Watershed, West Java, Indonesia

Agroforestry-based coffee is one of the conservation efforts to restore the damages at the Citarum watershed. Planting annual crops between coffee rows could potentially contribute income for the growers during the immature non-productive coffee growth. The aims of the research is to study the effect of various types of agroforestry models in the upstream Citarum watershed on the growth of coffee, and growth and yields of the intercrops. The research was conducted in September 2018 to June 2019 at the upstream Citarum watershed of Tarumajaya Subdistrict Kertasari, Bandung Regency, West Java, Indonesia. The research was arranged with a randomized block design with two factors. The first factor was the cropping system, i.e. coffee monoculture, coffee and corn, coffee and sweet corn, coffee and red beans, and coffee and habanero chili. The second factor was organic matter application, i.e. with and without application of in situ organic matter. The results of the research showed that coffee intercropped with habanero with application of in situ organic matter had the best vegetative growth, indicated by taller plants, more leaves, increased leaf P and Mg levels, and the maximum income from the intercrop. Coffee intercropped with corn with application of in situ organic matter had a maximum corn production but had the lowest income. Therefore, the model of coffee intercropped with habanero chili with application of in situ organic matter was the best model from several intercropping systems tested.

Productivity and beverage sensory quality of arabica coffee intercropped with timber species

Abstract: The objective of this work was to evaluate the productivity and beverage sensory quality of arabica coffee under the influence of tree species cultivated at different spacings. The experiment was set in 2012, in the municipality of Santo Antônio do Amparo, in the state of Minas Gerais, Brazil. A randomized complete block design was carried out with four replicates and seven treatments, as follows: Catuaí Vermelho IAC 99 Coffea arabica in monoculture (3.40x0.65 m); and this cultivar intercropped at two spacings (9.0x13.6 and 18.0x13.6 m) in the coffee row ‒ either with African mahogany (Khaya ivorensis), teak (Tectona grandis), or pink cedar (Acrocarpus fraxinifolius). Three coffee rows were fixed between rows, totaling 13.6 m between the wooded rows. Productivity, sensory analysis (cup test), and content analysis of sensory attributes were evaluated in the 2017 and 2018 crop years. The treatments and years of harvest influenced productivity. The sensory analysis was positive for coffee intercropped with African mahogany and teak, in 2018. Sensory attributes and nuances are modified by the years of harvest. Arabica coffee plants intercropped with African mahogany show a superior productivity, regardless of the spacing between species, as well as a higher sensory quality in the 2018 harvest.

Use of foliar fertilizers as attenuators of injuries caused by glyphosate drift in young coffee plantations

Glyphosate is the most used product for weed control in young coffee planting rows. The application is carried out in a directed way, avoiding the contact of the product with the crop. However, drift and consequent plant injuries frequently occur. An alternative to reduce these injuries is the use of attenuators capable of reducing the negative effects caused by this herbicide. Therefore, the objective of this study is to verify the efficiency of foliar fertilizers (Fertiactyl Pos® and Crop+) as attenuators of the toxic effects caused by the use of glyphosate in the coffee crop. Thus, coffee seedlings were subjected to different doses of the mixture of Fertiactyl Pos® with glyphosate and Crop+ with glyphosate. The treatments were applied on top of the plants. The percentage of coffee intoxication was evaluated at 14, 21, 28, 35, 42 and 70 days after application. At 90 days after application, height, leaf area and shoot and root dry matter were evaluated. Higher doses of glyphosate (1440 and 2880 g ha-1) without the use of attenuators caused intoxication levels close to 80% at 28 and 90 DAA. The use of Fertiactyl Pos® and Crop+ reduced the injuries caused by the application of glyphosate, regardless of the dose of herbicide and fertilizers, but with different levels of action. All the morphological variables measured suffered a negative action with the isolated use of glyphosate, with a tendency to recover when the attenuators were applied. It is concluded that the two attenuators were efficient in suppressing the deleterious effects of glyphosate on coffee plants affected by this herbicide. However, the attenuator Crop+ showed better recovery results. For 720 g ha-1 of glyphosate, the dose most used in the field, 8 L ha-1 is recommended for Fertiactyl Pos® and 4 L ha-1 for Crop+. Key words: Coffea arabica; Crop+; Fertiactyl Pos®; Injury; Weed control.

Young shade trees improve soil quality in intensively managed coffee systems recently converted to agroforestry in Yunnan Province, China

The trend of soil degradation in intensive open coffee systems is well-documented. This study highlights the impact of young shade trees on soil quality only 4 years after their intercropping with coffee. 18 young shade trees belonging to three tree species (Cinnamomum camphora, Bishofia javanica and Jacaranda mimosifolia) were selected in an intensive coffee system in Southern Yunnan. Soil samples (0–20 cm) were tested for chemical composition, soil communities and soil enzyme activities under their canopies and in open areas, both in coffee rows and inter-rows, once during the rainy and once during the dry season. Additionally, root systems were characterized using trenches. Soil water profiles and litterfall were monitored along the production cycle. Coffee yield was recorded for two consecutive years. We detected a positive impact of all shade tree species on soil chemical, biological and biochemical components, especially during the dry season. This positive impact included higher soil organic matter (+10%) and more abundant soil microbial communities (+64%) under shaded coffee than under open coffee. Furthermore, shaded coffee trees yielded as much as open coffee trees, except under C. camphora, probably due to high below-ground competition. These results demonstrate that carefully selected shade trees can rapidly contribute to preserving and/or restoring soil quality in intensive coffee systems, while maintaining high coffee yield.

SPATIAL VARIABILITY OF SOIL PENETRATION RESISTANCE IN COFFEE GROWING

The intensive use of machines in agriculture tends to cause soil compaction, which can hamper the expansion of root system and the absorption of water and nutrients, thus affecting the crop development. In view of the above, the present study aimed to identify critical zones of soil compaction, through the spatial distribution of soil penetration resistance (SPR), having positions within the coffee rows and soil depth ranges as variables. The study was performed in a coffee plantation of 7.32 ha, belonging to the Bom Jardim Farm, located in the municipality of Bom Sucesso, MG, Brazil. The SPR was measured using a penetrometer in the depth range from 0 to 0.40 m, with discretization in four layers of 0.10 m. The data were interpreted based on geostatistics, in order to identify if there is spatial dependence of the SPR and generate thematic maps demonstrating the variable’s spatial behavior. It is concluded that there is spatial dependence of soil penetration resistance, being possible to use geostatistical tools to generate thematic maps based on classes of soil penetration resistance. The values of SPR in the tractor trail, for layers from 0.10 to 0.20 and from 0.20 to 0.30 m, were classified in the high SPR class and could cause damage to the crop.

Intercropping of coffee with the palm tree, macauba, can mitigate climate change effects

Global climate changes can affect coffee production in Brazil, and in other coffee producing countries. We examined the potential for an agroforestry system with the native species, macauba (Acrocomia aculeata), to mitigate impacts on coffee production by reducing maximal air temperature and photosynthetic active radiation. The objective of this study was to investigate the influence of an agroforestry system with macauba on productivity, microclimatic characteristics and soil physical quality on a coffee plantation in the Atlantic Rainforest biome, in Southern Brazil. We measured soil attributes (moisture, temperature, and physical properties), microclimate conditions (air temperature, photosynthetic active radiation) and coffee production parameters (productivity and yield). Macauba palm trees were planted at different planting densities on the rows and distances from the coffee rows. Planting density of macauba and their distance from the coffee rows affected soil thermal-water regime. Compared with the traditional unshaded sole coffee planting, the intercropped cultivation provided more coffee yield on both macauba density planting and distance evaluated. On the other hand, coffee productivity was increased by agroforestry systems just for 4.2 m distance between palm trees and coffee rows. Planting density of macaubas did not affect coffee yield and productivity. Best coffee harvest in agroforestry systems with macauba was related to higher soil moisture at the depth of 20–40 cm, higher photosynthetic active radiation, and maximum air temperatures lower than 30 °C. Agroforestry with coffee and macauba trees can be an adaptation strategy under future climatic variability and change related to high temperatures and low rainfall.

Weed control methods and coffee shrub residue effects on carbon stocks in a Latosol under conservation management practices

Weed control methods in coffee crops can significantly influence carbon (C) stocks of soil humic substances. The aim of this study was to evaluate C stocks in an experimental coffee crop submitted to conservation agriculture for weed control between coffee rows. The study was carried out in a very clayey Dystroferric Red Latosol, Londrina, Paraná state (23°21’30” S; 51°10’17” W), cultivated with cultivar Mundo Novo IAC 379-19. In 2008, the experiment was established as randomized block design with four replicates within split-split plot scheme. Seven weed control methods between coffee rows were considered (hand weeding; portable mechanical mower; herbicides application; two cover crops; weed check and spontaneous). In September 2013, coffee shrub pruning was conducted and residues were distributed along inter rows. The weed control methods were considered as the main-plot factor and sampling period (March 2014 and February 2015) as the split-plot. Soil samples were collected at the center of the inter rows at four depth increments. C stocks evaluation included total organic carbon determination by chromic acid wet oxidation. Humic substances were characterized by UV-Vis spectroscopy. Most of the considered weed control methods did not affect organic carbon storage in 0 – 40 cm layer, nevertheless led to increase at topsoil. In 2015, the humin fraction C stock was 54 % higher at superficial layer than subsequent depth, presenting 39 % average increase at the 2014/2015 interval. Although C stocks from humic and fulvic acids did not vary, more conjugated/condensed characteristic for the fulvic fraction was observed.

Soil physico-hydrical properties changes induced by weed control methods in coffee plantation

Abstract Weed management between coffee inter rows plays a key role in minimizing soil degradation processes. Soil structure and, consequently, its pore size distribution (PSD), water retention (SWRC) and availability can be greatly affected by the weed control methods. In this study, the effect of six different weed control methods on pore size distribution of a Haplustox was analyzed. Two soil depths (0–3 and 10–13 cm) were investigated. Weed control methods in the inter row area were: no weed control; post-emergence herbicide (Glyphosate); mechanical mower; hand-hoe weeding; rotary tiller; pre-emergence herbicide (Oxyfluorfen). An adjacent area of native forest close to the field experiment was used as a reference. The application of different weed control methods produced alterations in the soil structure in relation to the native forest as observed by measurements of SWRC and PSD. The upper soil surface layer (0–3 cm) was more sensitive to changes than the lower surface layer (10–13 cm). In the inter row area (between coffee rows), the weed control methods hand hoe weeding, mechanical mower (both mechanical methods) and pre-emergence herbicide decreased the volume of pores responsible for water drainage, with equivalent pore radius >25 μm, in the layer 0–3 cm in relation to the 10–13 cm layer.

Chemical and hydrophysical attributes of an Oxisol under coffee intercropped with brachiaria in the Cerrado

Abstract The objective of this work was to evaluate the effect of irrigation and of the presence of brachiaria (Urochloa decumbens) between coffee (Coffea arabica) rows on coffee yield and on chemical and hydrophysical attributes of a Typic Haplustox. The study was conducted in the Cerrado region in Planaltina, Brasília, DF, Brazil, in a randomized complete block design, arranged in split-split plots, with four replicates. Water regimes (irrigated or rainfed) were assigned to the main plots, inter-row management systems to the subplots, and soil layers to the sub-subplots. The following soil attributes were determined: total organic carbon, total nitrogen, C/N ratio, carbon and nitrogen stocks, bulk density, aggregate stability, total porosity, macroporosity, low-retention microporosity, remaining microporosity, criptoporosity, and total and readily-available water, besides coffee yield. Irrigation of coffee plants, associated with brachiaria intercropped as a cover crop, increased coffee yield and favored chemical and hydrophysical soil attributes, improving soil structure and its ability to store water. Irrigation favors organic carbon stocks in the upper soil layers, whereas brachiaria favors soil physical attributes related to water availability to coffee.

Humic substances and its distribution in coffee crop under cover crops and weed control methods

Humic substances (HS) comprise the passive element in soil organic matter (SOM), and represent one of the soil carbon pools which may be altered by different cover crops and weed control methods. This study aimed to assess HS distribution and characteristics in an experimental coffee crop area subjected to cover crops and cultural, mechanical, and chemical weed control. The study was carried out at Londrina, in the state of Parana, southern Brazil (23°21’30” S; 51°10’17” W). In 2008, seven weed control/cover crops were established in a randomized block design between two coffee rows as the main-plot factor per plot and soil sampling depths (0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm) as a split-plot. HS were extracted through alkaline and acid solutions and analyzed by chromic acid wet oxidation and UV-Vis spectroscopy. Chemical attributes presented variations in the topsoil between the field conditions analyzed. Cover crop cutting and coffee tree pruning residues left on the soil surface may have interfered in nutrient cycling and the humification process. Data showed that humic substances comprised about 50 % of SOM. Although different cover crops and weed control methods did not alter humic and fulvic acid carbon content, a possible incidence of condensed aromatic structures at depth increments in fulvic acids was observed, leading to an average decrease of 53 % in the E4/E6 ratio. Humin carbon content increased 25 % in the topsoil, particularly under crop weed-control methods, probably due to high incorporation of recalcitrant structures from coffee tree pruning residues and cover crops.

Microclimate and development of Coffea canephora cv. Conilon under different shading levels promoted by Australian cedar (Toona ciliata M. Roem. var. Australis)

Coffee growers are searching for more sustainable production systems. Shaded cultivation is presented as a management option to attenuate coffee environmental stresses. This work aims at to evaluate the microclimate and coffee plant (Coffea canephora cv. Conilon Clone 02) development under different shading levels promoted by the intercropping with Australian cedar (Toona ciliata M. Roem. var. Australis) or under unshaded conditions. Australian cedar and Conilon coffee were planted in 15 × 2m and 3 x 1.2 m spacing, respectively, resulting in five rows of coffee to one row of Australian cedar. The closer the coffee rows were in relation to the Australian cedar trees the higher shade level was obtained. Climatic variables (temperature, irradiance and relative humidity) and leaf areas were evaluated over four seasons, and the internode lengths of plagiotropic and orthotropic branches were evaluated monthly. The 2013yield was also measured. There was a decrease in both the irradiance and temperature and an increase in the relative humidity at all times under shaded cultivation (closer to the Australian cedar row). The highest growth of plagiotropic and orthotropic branches and leaf expansion were found under shaded cultivation; however, the number of nodes per branch and the yields were similar among treatments. Growing Conilon coffee intercropped with Australian cedar showed a good yield potential.

Fertilidade do solo e estado nutricional do cafeeiro cultivado em atmosfera enriquecida com CO2

Resumo: O objetivo deste trabalho foi avaliar os efeitos de concentrações de CO2 atmosférico nos atributos químicos do solo, na linha (cafeeiro) e na entrelinha (braquiária), e nos teores de macronutrientes em folhas do cafeeiro. Utilizou-se o delineamento de blocos ao acaso, com parcelas subdivididas e seis repetições. Os tratamentos consistiram de dois níveis de CO2 atmosférico, 390 e 550 μmol mol-1. A amostragem de solo foi realizada na linha e na entrelinha do cafeeiro, em 2013 e 2014, nas camadas de 0-5,0, 5,0-10, 10-20 e 20-40 cm, e de 0-10, 10-20 e 20-40 cm, respectivamente. Avaliaram-se pH, teores de Ca2+, Mg2+, K, P e S disponíveis, saturação por bases e matéria orgânica do solo. Em 2013 e 2014, houve redução nos teores de P na linha do cafeeiro, com o aumento da concentração de CO2. Em 2014, houve redução nos teores de K disponível no solo e aumento dos teores de K na folha do cafeeiro sob 550 μmol mol-1 de CO2. Em cafeeiro cultivado em atmosfera enriquecida com CO2, o teor de P disponível no solo é o que mais reduz, o que indica a necessidade de reposição adequada deste nutriente.

Soil organic matter quality and weed diversity in coffee plantation area submitted to weed control and cover crops management

Soil organic matter (SOM) plays an important role for soil quality and productivity maintenance, acting as energy source, promoting biological diversity, enhancing terrestrial ecosystems composition. This study assessed the effects of long-term weed control and cover crops between coffee rows on SOM quality in a very clayey (80dagkg−1 of clay) Typic Haplorthox (Dystroferric Red Latosol) from State of Paraná, Southern Brazil. Seven weed control and cover crops were assessed between coffee rows: (i) hand weeding—HAWE; (ii) portable mechanical mower—PMOW; (iii) pré+post-emergence herbicides—HERB; (iv) peanut horse (Arachis hypogeae) cover crop—GMAY; (v) dwarf mucuna (Mucuna deeringiana) cover crop—GMMA; (vi) no-weed control between coffee row—SCAP; (vii) weed check—CONT. Soil samples were collected in the center of the inter-rows between coffee trees at four depths: 0–10cm, 10–20cm, 20–30cm, and 30–40cm. SOM quality assessment included total soil organic carbon (SOC) content and organic matter humification degree (HFIL) by laser-induced fluorescence spectroscopy (LIFS). C content was up to 26% higher for SCAP and CONT samples, compared to the other field conditions, denoting influence of plant material accumulation at top soil (0–10cm). Higher HFIL results (up to 47%) were observed at deeper layers, inferring incidence of less humified/labile structures at top soil, and condensed/recalcitrant character for organic matter at depth, regardless of cover crops and weed control method considered. In terms of weed density it was observed a higher negative impact on weed growth in areas under GMMA cover crop (decrease of 90.8% in weed density). The behavior may be attributed to the chemical composition of the species, ultimately leading to possible occurrence of allelopathic phenomenon.