Orchard Floor Management Systems Research Articles

Soil Nitrogen and Weed Biodiversity: An Assessment under Two Orchard Floor Management Practices in a Nitrogen Vulnerable Zone in Italy

Nowadays, understory vegetation along the tree row is considered a vital source of agroecosystem services and functional biodiversity improvement in the fruit orchard. Hence, current orchard floor management systems encourage practicing a more sustainable approach that supports vegetation cover rather than keeping bare soil herbicide use, or tillage. A two-year field trial was conducted using two different ground management techniques; integrated mowing (mower and brush or disc) and herbicide (glyphosate) in two commercial apple and peach orchards in a nitrogen vulnerable zone (NVZ) of the Marche region, Italy. This study aimed to evaluate the effects of these practices on soil N status, weed abundance, percent of soil cover, and dry weed biomass production. Weed management systems had no significant effect on soil organic matter and N availability; however, an improvement was noticed under integrated mowing when compared to the one treated with herbicides. Integrated mowing had a significant effect on species richness, soil coverage, and weed biomass production, which was approximately 2-times higher than in the herbicide-treated plots. The overall results showed that integrated mowing maintained a balance in the soil N status of both orchards, while supporting above-ground weed biodiversity and soil protection.

Effect of living mulch on physiological and biochemical parameters of cherry leaves and fruits with organic growing technology

In organic sweet cherry (Prunus avium L./Prunus mahaleb) orchard standard mechanical cultivation was compared with living mulch – spontaneous vegetation cover. Since 2013 the experimental orchard has been maintained with two different orchard floor management systems: standard mechanical cultivation (MC) – one discing at a 15 cm depth + manual weeding during the growing season was compared with living mulch (LM) – spontaneous vegetation cover. The natural vegetation of grasses was mowed 4 times during the growing season and the clippings were left on the ground for decomposition. Any other management was identical in each treatment. Synthetic fertilizers and chemical plant protection products were not used. It was established that total moisture content of the leaves was significantly reduced under LM (over 2 years) or did not differ significantly from MC (1 year). The water-retaining ability of the leaves did not differ significantly between LM and MC (2 years) or was higher in the conditions of LM (1 year). The total leaf area at the beginning of the study (1 year) was larger in MC conditions. In the following year, the difference between LM and MC was insignificant. In 2019, the total leaf area was significantly larger in the conditions of LM. An increase in the total leaf area under LM conditions led to a significant decrease in the specific surface density of the leaves, the accumulation of chlorophylls in them, and a decrease in the ratio of chlorophylls (a/b) due to an increase in the content of chlorophyll b (compared to the MC conditions). The difference in fruit size parameters, average weight of the fruits, total soluble solids, total sugars, titratable acidity, sugar-acid index were insignificant between LM and MC. Ascorbic acid and total anthocyanins content of sweet cherry fruit was significantly increased under LM conditions compared to MC. The results show that cherry trees gradually adapt to coexistence with natural herbs and, during stress, accumulate more physiologically active substances in the fruit. Key words: sweet cherry, organic orchard, living mulch, total leaf area, specific leaf density, chlorophylls, fruit size, ascorbic acid, anthocyanins.

Floor Management Systems in an Organic Apple Orchard Affect Fruit Quality and Storage Life

In an organic apple orchard, standard mechanical cultivation was compared with four different orchard floor management systems (OFMS): acetic acid (V), living mulch (L), a sandwich system during the growing season (SSS), and a sandwich system during the whole year (SSW). The effects of these OFMS on weed management, soil conditions, tree growth, tree yield, fruit quality, and fruit storage potential in a cool climate were evaluated. Acetic acid treatment showed good weed suppression without any amendatory effect on soil conditions, fruit quality, or tree performance. The L and SSS systems increased soil respiration, decreased tree vigor, and improved fruit quality, but had no sufficient influence on weed competition and thus decreased fruit yield. Only SSW gave better weed control, higher soil respiration, and acceptable tree growth with no yield reduction. Fruit from this system also showed better quality at harvest than fruit from other OFMS and maintained this good quality during storage. A 6-week weed-free period from late May to mid-July gave the highest apple yield in two OFMS (SSW and V).

Soil properties under different orchard floor management systems for organic apple production

Orchard floor management impacts soil conditions and thus tree performance. This research was initiated to investigate the effects of alternative orchard floor management systems compatible with organic production on soil parameters using the "Pacific Gala" apple cultivar (Malus × domestica Borkh.) onthreerootstocksofvaryingvigor.Alfalfahay mulch, propane flame burner, and Swiss sandwich sys- tem(combinationofresidentvegetationandtilledstrips) were compared from 2001 to 2005. These treatments were applied to tree rows which provided different vegetation-free areas. Contrasting additions of organic matter were evaluated for their effect on soil organic matter (SOM), C content, nitrate and ammonium availability, moisture, and soil food web through nema- tode populations. Laboratory incubations to determine C and N mineralization potentials were performed. Dur- ing this time period, SOM increased under the mulched soil and slightly less under the Swiss sandwich system (SSS) but in this last case without external inputs. Carbon and N pools were not impacted by flame burn- ing (FL) but were enhanced by alfalfa hay mulch (MU) and to a lesser extent by SSS. Nitrate-N content in soil under MU increased between five and ten times com- pared to SSS and FL. Total number of nematodes was higher for SSS and MU compared with FL treatment; however, SSS had the most structured soil food web, an important sustainability trait, while MU had the least.

Influence of Orchard Floor Management and Compost Application Timing on Nitrogen Partitioning in Apple Trees

Synchronizing the supply of plant-available nitrogen (N) from organic materials with the N needs of apple trees is essential to cost-effective organic apple production. Tree growth and organic matter mineralization are affected by orchard floor management. This study examines the effects of three orchard floor management systems, cultivation, wood chip mulch, and a legume cover crop, on the accumulation and partitioning of compost-derived N in young apple (Malus domestica Borkh.) trees at different compost application dates across two growing seasons. Compost enriched with 15N was applied to apple trees in April, May, and June of 2006 and 2007, and trees were excavated in Sept. 2007 to determine the fate of labeled compost N. Trees with wood chip mulch had significantly greater dry weight and N accumulation in vegetative tree components than trees with cultivation or legume cover. Fruit yields were similar between cultivation and wood chip treatments despite less vegetative growth under cultivation, as these trees partitioned more dry weight into fruit (44%) than wood chip mulch trees (31%). Nitrogen-use efficiency by trees was lower with a living legume cover crop than in other treatments due to competition for resources. In the cover crop aboveground biomass, 20% to 100% of the N was derived from compost. In comparison, only 5% to 40% of N in the decomposing wood chip mulch originated from compost. Tree reserves were an important source of N for spring fruit and leaf growth in all treatments, but significantly more so for trees in the cultivation treatment. Fruit and leaves were strong sinks for compost N early in the season, with trees allocating 72% of spring N uptake into leaves and fruit. In the summer, N uptake increased improving compost N-use efficiency. Summer N was preferentially allocated to perennial tissues (71%), bolstering N reserves. Trees with wood chip mulch performed well and had greater capacity to build N reserves, making wood chips ideal for establishing young organic apple orchards. However, as the orchard matures, it may be beneficial to switch to a groundcover that reduces tree vegetative growth.

Organic Orchard Floor Management Systems for Apple Effect on Rootstock Performance in the Midwestern United States

In organic apple production systems, orchard floor management is of prime importance because it determines weed management and soil fertility. In this experiment, we evaluated the response of the cultivar Pacific Gala on three rootstocks of different vigor: M.9 NAKB 337, M.9 RN 29, and Supporter 4 (in respective order of vigor from dwarfing to semivigorous). The rootstocks were also evaluated for the response to three orchard floor management systems (OFMSs): mulching using alfalfa hay, flame burning, and shallow strip tillage using the Swiss sandwich system (SSS). The experiment was conducted in an experimental orchard planted in 2000.

Response of Young Apple Trees to Grass and Irrigation

ABSTRACT Ground covers and irrigation are important components of orchard floor management systems that affect fruit tree vigor and productivity. Three experiments were conducted in a greenhouse to determine the relative water use of candidate ground covers (roughstalk bluegrass, RB, Poa trivialis), Chewing's fescue (CH, Festuca rubra subsp. commutata Gaudin), creeping red fescue (RF, Festuca rubra L. subsp. rubra), tall fescue (TF, Festuca arundinacea Schreber, Fawn), and perennial ryegrass (PR, Lolium perenne L., ‘Saint’) and the response of apple trees to those ground covers and to drip irrigation applied at two soilless substrate depths. Grass ground covers with large and deep root systems (TF and PR) used more water than a shallow- rooted grass (RB) and leaf water potential decreased more rapidly in apple trees grown with TF than RB when irrigation was withheld. Although apple tree shoot growth was greater with shallow- than deep-rooted grass, photosynthesis, transpiration, and root biomass distribution were not differentially affected by grass type. When grown with RB or TF, irrigation depth affected apple tree growth. During the first season in the greenhouse, deep irrigation at 37 cm depth increased apple root length density near emitters but shoot growth was less in apple grown with deep irrigation compared with apple grown with surface irrigation (0 cm) and with split irrigation at 0 and 37 cm. During the second season in the greenhouse, deep irrigation was beneficial to trees grown with grass that had large, deep root systems (TF) but it did not completely overcome interference effects of grass on apple trees, regardless of grass root system size or distribution. The results indicate that grasses with shallow root systems may be grown beneath apple trees and that split irrigation at two depths can provide flexibility that is necessary for water management of ground covers and apple trees.

Fine Root Dynamics in an Organic Apple Orchard under Two Ground Floor Management Systems

Fine root dynamics, timing of the events, and their relationship with soil conditions are of major interest because the understanding of these phenomena will permit a better synchronicity between nutrients and plant uptake. The goal of this research is to study the effect of different soil conditions, generated from two ground floor management systems, on fine root dynamics of apple trees under organic protocol in Michigan. The research has been conducted at the Clarksville Horticultural Experimental Station (CHES) of Michigan State University (MSU), in the organically certified (by OCIA) orchard of “Pacific Gala” grafted on M9 NAKB 337, established in May 2000. The orchard floor management systems being studied are: 1) a mulch made of alfalfa hay on the tree rows, with a width of 1.8 m and 2) the “Swiss Sandwich System” (SSS) that consists in superficial tillage of two strips 80 cm wide at each side of the tree row, leaving a 40 cm strip in the middle (on the tree row, under the canopy) where volunteer vegetation is allowed to grow. Root dynamics are studied on four replicas of two trees per each of the two ground treatments (16 in total) in a block design. For each tree in the trial four clear butyrate minirhizotrons have been installed (64 in total) at a 45° angle facing the tree, in the summer of 2002. Root dynamics, measured through pictures taken with a Bartz Technology digital camera and analyzed with a new software under development at MSU. During the 2003 season differences between the two systems have been found depending on the parameter taken in consideration. Mulch had different root distribution compared to SSS. Mulch treatment showed shallower roots even if below 90 cm the two systems didn't show any difference.

Nitrogen Uptake in a Range of Alternative Orchard Floor Management Systems

The percentage of N from fertilizer removed from the field by fruit trees is low. Overapplication of N in orchards has been a common practice and is a concern due to environmental and tree growth problems caused by excess N. Orchard floor management practices (OFMP) can improve the physical and chemical properties of the soil and may alter the soil biological community. Biological activity can affect mineralization rate and thus nutrient availability. The purpose of this study was to determine the effect of alternative OFMP on fertilizer N uptake. Research plots were located in Corvallis, Ore. (COR) (7-year-old `Fuji'), and Hood River, Ore. (HR) (3-year-old `Red Delicious'). Treatments were begun in 2001 in a split-plot completely randomized design with three replications. Main plot treatments were herbicide or cultivation. Subplot treatments were no amendment, bark mulch, compost, and barley/vetch mown and blown into the tree row. Depleted NH3SO4 was applied to single-tree replicates at budbreak. Trees were destructively harvested at harvest of 2003. At HR, the percentage of N derived from fertilizer (NDFF) was significantly lower in the whole tree, leaves, new wood, old wood, spurs, and roots of trees from compost than from unamended plots (P < 0.05). At COR, the NDFF in the leaves, fruit, new wood, spurs and roots was significantly lower in trees from compost plots than unamended plots (P < 0.05). The NDFF also tended to be lower in trees from bark mulch-treated plots than control plots, although differences were not always significant. Vetch/barley amendment resulted in NDFF similar to no amendment. There were no significant differences between the total N of trees from unamended and compost plots. Trees from compost-treated plots appear to be acquiring N from sources other than fertilizer.

Soil nitrate levels as influenced by apple orchard floor management systems

Mulches are an alternative to herbicidal control of weeds in orchards. Mulches may affect soil nutrient levels and consequently alter tree growth, fruit yield, and quality. The objective of this study was to determine the effects of cultivation, straw mulch, geotextile mulch, grass cover, a cover crop mixture of lupin and wild carrot, and manure compost mulch on extractable soil nutrients in two newly established dwarf apple orchards in Quebec. In 1992, manure compost and straw mulches resulted in higher soil NO3−-N and K relative to those levels under ground cover. Levels of soil NO3−-N were related to soil water content under any particular mulch. Straw mulch resulted in high July NO3−-N levels and low September levels of soil NO3−-N. Geotextile and cultivation treatments resulted in higher September NO3−-N levels relative to July. Soil under manure compost tended to have higher P levels than soil under other treatments. There was little or no effect of mulch treatments on extractable levels of soil NH4+-N, Ca, or Mg. Key words: Orchard, apple, mulches, geotextiles, straw, nutrients, manure compost, grass sod

Peach Tree Vegetative and Root Growth Respond to Orchard Floor Management

Peach (Prunus persica L. Batsch. `Biscoe'/Lovell) trees were grown in a sandy loam soil under six orchard floor management systems, including five vegetative covers (continuous under the tree) and a vegetation-free control (bare ground). At the end of the fifth year, trees grown in bare ground and nimblewill grass (Muhlenbergia schreberi J.F. Gmel.) had a significantly larger trunk cross-sectional area (TCSA) than trees grown in weedy plots, centipedegrass [Eremochloa ophiuroides (Munro) Hack.], or bahiagrass (Paspalum notatum Flugge). Trees grown in brome (Bromus mollis L.) did not differ significantly in TCSA from any other treatment. Soil profile excavations of the root system revealed that trees grown in bare ground or with nimblewill had significantly higher root densities than those in the weedy plots or grown with bahiagrass. Vector analysis of root distribution indicated that trees grown in bare ground or nimblewill rooted deeper than trees in all other treatments. The greatest reduction in deep rooting occurred with bahiagrass.

ORCHARD FACTORS AFFECTING TREE PRODUCTIVITY AND MITE INFESTATIONS IN ARKANSAS

Twelve apple orchards and an experimental orchard were evaluated in 2 years for weed population and diversity, primary pests (codling moth, oriental fruit moth, plum curculio and mites), primary diseases, soil water content, and 37 horticultural attributes describing tree growth, fruit growth, productivity, tree nutrition, and management intensity. Data were collected at 2 week intervals. The experimental orchard contained three apple cultivars grown in three orchard floor management systems. Increased weed ground cover related to earlier and increased mite predator populations in trees, decreased pest mite-days, but reduced tree and fruit growth. Grass weed species appeared more detrimental to tree growth than broadleaf species. Tree training intensity was negatively related to canopy density, and incidence of pests and diseases. Reductions in fruit size and quality were more closely linked to weed competition, and earliness and degree of pest mite infestation than to crop load.

COMPETITIVE VEGETATIVE ORCHARD COVERS REDUCE PEACH ROOTING

Peach trees (`Biscoe'/Lovell) were planted in March, 1988 in ten different ground cover management systems. The trees were planted at the Sandhills Research Station in Southeastern North Carolina on a Candor sand and Eunola sandy loam. In December, 1991 the trench profile method was used to evaluate root distribution under the six orchard floor management systems of nimblewill, bare ground control, centipedegrass, brome, bahiagrass, and weedy control. Trenches were dug parallel to the tree row 60 cm from the center of the row on both sides of the tree. Grids 1 meter square, sectioned into 10 cm squares, were placed on the profile walls and root distribution (in three size categories) was recorded for 1 meter on each side of the tree in each trench. Root numbers were greatly reduced under the vegetative covers that provided the greatest suppression of vegetative tree growth. Total root densities under the trees in the vegetative covers were ranked into three size categories which were correlated with the amount of vegetative tree growth.

Canopy-Air Temperature Differences and Soil Water as Predictors of Water Stress of Apple Trees Grown in a Humid, Temperate Climate

Temperature differences between tree canopies and air (Tc - Ta) and between leaves and air (T1 - Ta) of apples (Malus domestics Borkh. `Royal Gala') grown in New Zealand were measured with infrared (IR) thermometry. Treatments included three orchard-floor management systems and irrigation withheld (WI) for part of the growing season. Measurements of soil moisture indicated that, under full irrigation (FI), an alfalfa orchard-floor system apparently had higher soil water content than herbicide-strip (H) or plastic-mulch systems, whereas under the drought stress of WI, the H system retained the most water. The Tc - Ta and T1 - Ta of the WI treatment were significantly greater than those of the FI treatment after a soil-moisture differential was established. Linear regression between Tc - Ta, or T1 - Ta, and vapor pressure deficit (VPD) exhibited variable responses among dates. A crop water stress index (CWSI) was calculated from environmental measurements. The calculated CWSIS were not related to soil-moisture measurements. Even 35 days after full irrigation had been reinstated on the WI plots, the Tc - Ta, T1 - Ta, and CWSI of the WI plots were still significantly greater than those of the FI plots. These discrepancies in IR thermometry-based water-stress indices may be due to increased errors in the calculation of minimum CWSI at low VPDS and to fluctuating solar radiation and evapotranspiration, which are prevalent in humid, temperate climates.

Similarity of Peach Bud Development and Cold Hardiness in Orchards with Different Floor Management Practices

Abstract Orchard floor management has been found to affect the microclimate both seasonally (4) and on radiation frost nights (1, 3). Altering orchard climates by floor management could potentially modify bud hardiness and development due to radiative and convective heat transfer from the soil to the bud. However, information is unavailable to support this contention. This study was designed to investigate peach bud development and hardiness under two different orchard floor management systems.