Pine Needle Mulch Research Articles

Peach (Prunus persica L. Batsch) perfection: Boosting yields with mulching

The present study aimed to investigate the effects of various mulching strategies on the growth and yield of peach crops, as well as on soil hydrothermal regimes, weed infestation, and microbial properties. A field experiment was conducted, implementing various organic residue mulches including locally available grass and pine needle mulch, as well as inorganic mulches such as black and transparent mulch, control treatment comprising blanket recommendation. Results indicated that plots with black polythene mulch showed the highest fruit productivity, fruit yield, fruit length and diameter. Furthermore, black mulch and mulch mat treatments demonstrated complete weed control efficiency. Weed species Anagalis arvensis showed the highest maximum frequency, density, relative frequency, and relative density, while Biden pilosa had the highest abundance and relative abundance. The study also found that the impact of grass and pine mulch was of interest, as it helped regulate soil hydrothermal regimes and significantly enhanced total viable count, microbial activity, and microbial biomass carbon. In conclusion, these findings emphasize the potential of mulching techniques to improve peach crop yield and soil health.

The Application of Biochar from Waste Biomass to Improve Soil Fertility and Soil Enzyme Activity and Increase Carbon Sequestration

Biochar (BC) is a material that has many applications in agricultural and environmental activities. The aim of the study was to define the influence of BC produced in low-temperature pyrolysis from various organic waste materials, including one-month-old compost (OMOC), pine bark (PB), pine needle mulch (NM), pine cones (PC) and maple leaves (ML), on soil enzyme activity as well as its relation with organic matter properties. A 60-day incubation pot experiment was set up to investigate the influence of BC amendment on soil (S) characteristics. After incubation, we investigated the activity of soil enzymes, the content of available phosphorus (AP), potassium (AK) and magnesium (AMg), total organic carbon (TOC), total nitrogen (TN), dissolved organic matter (DOM) and its fractional composition (content and share of carbon and nitrogen of humic (CHAs, NHAs) and fulvic (CFAs, NFAs) acids and humin fractions). The effect of the amended biochars differed depending on the feedstock material. In general, the use of biochar enriched the soil with AP, AK and AMg increased the soil carbon stock, increased the intensity of nitrogen transformation and influenced the soil enzyme activity. OMOC and ML biochars significantly increased soil fertility, which was expressed by the high value of the CHA/CFA ratio.

Effects of Three Cultural Practices on Drosophila suzukii (Diptera: Drosophilidae) in Open Blueberry Fields in Florida.

Simple SummaryThe spotted-wing Drosophila is an invasive pest of berry fruits in Florida. The pest is difficult to control with pesticides, and resistance is developing. The current study was carried out in north Florida to see if non-pesticidal pest control tactics using three mulching practices could reduce its population density to increase growers’ berries productivity. The experiments were conducted for two years while using two plant-based mulches (short pine needles and pine bark) and one fabric-based mulch in the open blueberry fields. In general, the fly population was reduced within the selected pine bark and black weed fabric mulches. This is the first report of such practices deployed to manage the spotted-wing Drosophila in Florida. We are confident that these selective cultural practices could be utilized in open blueberry fields before berries settings to reduce pest pressure for both conventional and organic blueberry growers in Florida. Indeed, this will increase growers’ berry production and profitability.The spotted-wing Drosophila (SWD), Drosophila suzukii, is native species in Southeast Asia. For over a decade, this invasive pest has been globally expanding. The economic losses to soft fruits and stoned fruits in the United States are increasing every year. Presently, the only viable tool to reduce the SWD population is the continued use of broad-spectrum insecticides. Pesticide resistance is appearing in the populations for the SWD. Organic farmers have limited options to control this pest in open fields. The major goal of this study was to develop cost-effective pest management strategies to manage the SWD using three types of mulches (two plant-based and one fabric-based) to reduce fly population and damage in open blueberry fields in north Florida. The study was conducted in two fruiting seasons (2017 and 2018). The study results demonstrated that the fly trap catches in 2017 shortleaf pine needle mulch had much higher populations (about 2.5-fold) of the SWD than all other treatments. In 2018, the numbers were about 1.7-fold more on shortleaf pine needle mulch than on other treatments. The fine texture of the mulch (pine needles) can easily facilitate the emergence of the SWD if the mulch is not thick enough. Although the pine needles covered the soil surface, it may have been too thin and thus allowed the SWD adults to emerge from the soil without much hindrance. In 2018, a higher population of the SWD was recorded from all the mulching practices. However, there were no significant differences in trap catches between all treatments. In general, the fly population is reduced with the use of pine bark and black weed fabric mulches. This is the first study that reports the effects of three mulches in controlling the SWD populations, which could benefit conventional and organic blueberry growers.

Influence of different organic mulches on soil hydrothermal and plant growth parameters in potato crop (Solanum tuberosum L.)

Present study was conducted to investigate the effect of different mulching materials on soil hydrothermal environment and plant growth parameters for potato crop at field experimental station of National Institute of Technology, Hamirpur in the humid sub-tropical agro climate of Western Himalayas. The field experiments were conducted in a randomized complete block design with four mulching treatments; wheat straw mulch, pine needle mulch, rice straw mulch and no mulch in three replications. An increase in soil moisture retention ranging from 5.14% to 42% was observed depending upon the mulch material and depth of the soil layer in root zone. Mulching also reduced the daily maximum soil temperature up to 3.5ºC with an average temperature reduction of 1-2ºC during the period of tuber formation. Mulching produced beneficial effects on root depth, plant height, leaf area index and tuber yield. Mulching helped to bring about a yield surplus of 1.7-4.4 tonnes ha-1 over unmulched conditions and an increase in water use efficiency which varied from 13.5% in rice straw mulch to 34.9 % inwheat straw mulch.

Effect of mulching and planting density on production of sweet banana pepper (Capsicum annuum L.)

The present experiment was carried out at Dr Y S Parmer University of Horticulture and Forestry, Nauni, Solan (HP) during Kharif 2019 to study the effect of mulching and planting density on production of Sweet Banana pepper in mid hills of Himachal Pradesh. The experiment was laid out in Randomized Complete Block Design (Factorial) with three replications. The twelve treatment combinations comprised of combination of four different mulches (M) viz., no mulch (M0), pine needle mulch (M1) black-plastic mulch (M2), silver-black plastic mulch (M3) with three planting densities (P) viz., 60 cm×60 cm (P1) 60 cm×45 cm (P2) and 60 cm×30 cm (P3). The observations were recorded on growth yield and quality traits, fruit rot incidence (%), weed count, fresh and dry weight of weeds, soil moisture and temperature. The treatment combination silver-black plastic mulch with plant spacing of 60 cm×30 cm (M3P3) was found superior over all other treatment combinations for most of the growth and yield parameters, quality traits, fruit rot incidence and weed control as well as performed well in improving soil moisture and temperature. This treatment combination also had maximum benefit: cost ratio of 4.21:1. Hence silver-black mulch in combination with 60 cm×30 cm spacing can be recommended for commercial cultivation of Sweet Banana pepper in North Western Himalayan regions after multi-locational testing.

Effect of organic mulches on agronomic parameters – a case study of tomato crop (Lycopersicon esculentum Mill.)

Purpose ThePresent study was conducted to investigate the effectiveness of locally available organic mulches on moisture retention, yield and irrigation water use efficiency in tomato crop. Methods The crop was grown in a randomized complete block design using pine needle mulch, wheat straw mulch and rice straw mulch as treatments and no mulch serving as control. Results Mulches were able to increase the soil moisture retention through 0.1 m to 0.5 m soil depth. Though mulches behaved differently in soil moisture retention at various depths, the average moisture retention observed for pine needle mulch, rice straw mulch, wheat straw mulch and no mulch was 22.18 %, 21.01 %, 18.52 % and 18.23 %, respectively. The mulches brought about a soil temperature reduction to an extent of 3.3 °C in maximum daily temperature and 1.4-1.8 °C in average soil temperature at 14:00 o'clock during the crop period. The positive effect produced on soil hydrothermal environment was directly reflected through increased leaf area index, plant height and yield. The trend of favourable effect produced by mulches on growth parameters was pine needle mulch > rice straw mulch > wheat straw mulch > no mulch. Mulching increased irrigation water use efficiency by 28.9%, 26.6 % and 12.5 % in pine needle mulch, rice straw mulch and wheat straw mulch, respectively over no mulch. Conclusion Locally available organic materials can effectively be used to increase soil moisture retention, enhance yield and irrigation water use efficiency in tomato crop.

Effect of Pine Needle Mulch and Irrigation Frequency on the Yield of Origanum syriacum under Open Field Condition

Due to the intensive harvest from natural habitat and increasing competition as a source of food, O. syriacum was introduced into cultivation and soon became one of the promising crops for many farmers in rural areas. The aim of the study is to investigate the effect of pine needle mulch(PN) and irrigation frequency(IF) at 5, 10 and 15 days on the yield under open field conditions. The study was conducted at the Lebanese agricultural research institute (LARI) in Lebaa station (33°32.681′ North, 35°27.088′ East, 354 m a.s.l.), south Lebanon, province of Jizzin, under open field condition for two seasons during 2016. Treatments were organized in randomized complete block design (RCBD) with three replicates. The results indicated a significant effect of mulch in both spring and fall seasons F (1, 172) = 59.34, p < .0001, η²=.24, F (1, 172) = 77.71, p < .0001, η²=.30 respectively. The two-way anova showed no significant effect of irrigation frequency on the average and total plant fresh weight (PFW) across two seasons F (2, 349) = .80, p= .4522, η²=.0038, F (2, 159) = 1.07, p= .3460, η²=.007 respectively. Very little variance of the plant fresh weight ,(0.2% – spring and 3.1 %- fall) was attributed to the interaction of mulch and irrigation frequency .In a comparison between percent weight contribution(PWC) of a different plant part, leaves formed the highest proportion (48.6%) compared to the inflorescence and stem. The fresh weight of weeds(g/ m2 ) was significantly less in plots mulched with pine needles compared to the control (F(1,66)=24.43, p<.0001, η²=.75).
 Applying pine needle mulch enhanced most of the yield parameters. Under calcareous clayey soil O. syriacum could be irrigated at10 or 15 days frequencies without remarkable decrease in the yield.

Weed suppression, nutrient leaching, water use and yield of turmeric (Curcuma longa L.) under different land configurations and mulches

Alteration in micro-topography and mulching are important agronomic practices to conserve the resources in situ. Turmeric is sensitive to weed infestation and soil loss. Studies were conducted during 2011–12 and 2012–13 in a silt loam soil to evaluate the weed suppression, nutrient leaching, water use and yield of turmeric under varying land configurations [broad bed and furrow (BBF), ridge and furrow (RF), and flat bed (FB)] and mulch materials [paddy straw followed by weed biomass (PS), thatch grass (Imperata cylendrica; IC), pine needle (PN) and no mulch (NM)]. Results revealed reduced weed density, dry biomass and superior weed suppression with BBF and either of mulch. Weed suppression followed the trend from higher to lower with PN > IC > PS > NM. The soil and nutrient (nitrogen, phosphorus and potassium) losses under BBF and PN mulch were the lowest, indicating better conservation of the soils. Besides, the rhizome yield, water use efficiency, economic and energy parameters were improved by following higher to lower with BBF > RF > FB and PN > IC > PS > NM. Land configuration and mulch suppress the weed growth, reduce the soil and nutrient losses, leading to higher rhizome yield, enhanced water use, superior economics and improves energy values.

Yield Performance of Organic Sweetpotato Varieties in Various Mulches

Interest in organic sweetpotato production in the United States has been growing as consumers and producers are becoming increasingly concerned about how their food is cultivated. Thus, there is a growing need for information on sweetpotato production and variety selection under an organic management production system. The objective of this study was to evaluate the effects of various mulches on yields—total and marketable—of fourteen sweetpotato varieties grown under organic management. Three types of mulch, wheat straw, pine needle, and black plastic, and a control (no mulch) were evaluated during the 2016 growing season. The wheat straw mulch yielded significantly higher yields than the black plastic and pine needle mulch treatments, though it was not significantly different from the control. The total and marketable yields of sweetpotato roots also varied significantly among the varieties, ranging from 39,719 kg·ha−1 for Beauregard to 4925 kg·ha−1 for O’Henry. There was a significant interaction between variety and mulch treatment on total but not marketable yield. More research is needed to ascertain the stability of the effects of varieties, mulch treatment, and their interactions on total and marketable yields and to elucidate other treatments and varieties with better potential to improve sweetpotato yields in organically managed production systems.

Effectiveness of Polyacrylamide, Wood Shred Mulch, and Pine Needle Mulch as Post-Fire Hillslope Stabilization Treatments in Two Contrasting Volcanic Soils

Post-fire hillslope stabilization treatments aim to reduce runoff-erosion risks following forest fires by counteracting the impact of fire on key soil and hillslope properties. Here we evaluate the effectiveness of wood shred mulch, long-leaved pine needle mulch, and polyacrylamide (PAM) in reducing post-fire runoff and erosion in two volcanic soil types of contrasting wettability using rainfall simulations (55 mm h−1 for 30 min) at the microplot (0.25 m2) scale. The cover provided by the wood shreds and pine needles led to a reduction of runoff and erosion in both the wettable—(62% and 92%, respectively, for wood shreds, and 55% and 87%, respectively, for needle mulch) and the extremely water-repellent soils (44% and 61%, respectively, for wood shreds). In contrast to what might be expected, PAM did not reduce runoff or erosion when applied to the extremely water-repellent soils, suggesting that PAM should not be applied in this terrain type. Although more research is needed to determine whether the high effectiveness of pine needle mulch and wood shred mulch fully translates to coarser scales, the results are encouraging in terms of these materials’ ability to provide effective and relatively economic mitigation treatments for fire-induced runoff-erosion risks in volcanic soils.

Tillage system and organic mulch influence leaf biomass, steviol glycoside yield and soil health under sub-temperate conditions

Tillage system and organic mulch play important role to increase plant growth, soil organic carbon (SOC) and soil nitrogen (N) in sustainable agricultural production system. However, the short term (≤5 years) effects of tillage system and organic mulch on crop yield, SOC and N dynamics are often complex and inconsistent. Moreover, the effects of tillage system and levels of organic mulch on stevia (Stevia rebaudiana) are not documented, particularly in the western Himalayan region. Thus a field experiment was conducted with eight treatment combinations comprising two tillage practices (zero and conventional) and four levels of pine-needle mulch (no-mulch, 5tha−1, 10tha−1 and 15tha−1). The conventional tillage registered about 22 and 32% higher dry leaf yield compared with zero tillage practice in 2012 and 2013, respectively; however, remained statistically at par (P≥0.05) with zero tillage in 2014. The stevioside, Reb-A, and total steviol glycosides accumulations in leaf were not affected by the tillage system. The significantly (P≤0.05) higher available K was recorded with zero tilled soil. The effects of mulch were more pronounced, and the maximum leaf yield was recorded with the mulching at 15tha−1 but remained at par (P≥0.05) with the application of 10tha−1. Moreover, available soil N and SOC were also higher with the mulching at 10 and 15tha−1, respectively. Hence, the zero tillage is not effective for increasing crop productivity in short term; nevertheless, higher yield, SOC, and soil nitrogen can be achieved by the application of optimum level of organic mulch.

Ground and Rove Beetles (Coleoptera: Carabidae and Staphylinidae) are Affected by Mulches and Weeds in Highbush Blueberries

Biological control of insects by predators may be indirectly influenced by management practices that change the invertebrate community in agroecosystems. In this study we examined effects that mulching and weeding have on predatory beetles (Carabidae and Staphylinidae) and their potential prey in a highbush blueberry field. We compared beetle communities in unweeded control plots to those that were weeded and/or received a single application of compost or pine needle mulch. Compost mulch and weeding significantly affected the carabid community while the staphylinid community responded to compost and pine needle mulches. Effects because of mulch tended to intensify in the year after mulch application for both families. Estimates of species richness and diversity for Carabidae and Staphylinidae were similar in all plot types, but rarefaction curves suggested higher Carabidae richness in unmulched plots despite fewer individuals captured. Carnivorous Carabidae, dominated by Pterostichus melanarius, were most frequently captured in compost plots both years, and omnivores were most frequently captured in unweeded compost. Density of millipedes, the most abundant potential prey, was generally greater in mulched plots, whereas seasonal abundance of small earthworms varied among mulch types. Our results have potential implications for biological control in mulched highbush blueberries depending on beetle consumption rates for key pests and how rates are affected by alternative prey.

Diferentes substratos na produção de mudas de mirtileiro

O objetivo desse trabalho foi avaliar o efeito da composição de diferentes substratos na produção de mudas de mirtileiro. Foram utilizadas mudas da cultivar 'Georgiagem', oriundas de multiplicação in vitro. Foram utilizados sete diferentes substratos, os quais são: T1 - Plantmax® (100%); T2 - Plantmax® + perlita (1:1); T3 - Solo + matéria orgânica + perlita (1:1:1); T4 - solo + casca de arroz (1:1); T5 - solo + composto industrial + vermiculita (1 :1:1); T6 - casca de acácia + solo (1:1); T7 - acícula de pinus + solo - (1:2). O substrato acícula de pinus + solo, seguido pelos substratos Plantmax®, casca de acácia + solo e casca de arroz + solo promoveram maior acúmulo de massa seca da parte aérea e raízes. Os substratos solo + composto industrial + Perlita e Solo + composto industrial + vermiculita, com pH alcalino, apresentaram menor produção de massa seca e menores concentrações de Fe, Mn, Zn, N e P. Os substratos acícula de pinus, casca de acácia + solo, casca de arroz + solo e Plantmax® com ou sem perlita, mostraram-se os mais adequados para a produção de mirtileiro, cultivar 'Georgiagem'.

Mulch type and moisture level affect pupation depth of Rhagoletis mendax Curran (Diptera: Tephritidae) in the laboratory

Mulching can be beneficial for organic highbush blueberry production, but its effects on insect pests have received little attention. For pests that pupate in soil, depth may affect pupation success due to differences in temperature and moisture, mortality factors such as predation, or efficacy of controls such as insecticidal soil drenches. We examined how mulch type and moisture affect pupation depth for Rhagoletis mendax Curran (blueberry maggot), an important pest of blueberries. In laboratory studies, pupation depth was measured in wood waste compost, uncomposted pine needles, soil and sand, each at dry, field moisture levels and wet, 99% water holding capacity conditions. Pupation occurred more deeply but with greater variability in pine needle mulch compared to compost mulch, soil, or sand. Approximately 50% of maggots pupated on the surface of wet soil, however, maggots burrowed more deeply in wet than in dry pine needles. Moisture level did not significantly affect pupation depth in compost or sand. Some larvae unexpectedly escaped the stacks of cups used to assess pupation depth or died before forming a puparium. Less than 70% of stacks with dry pine needles contained pupae, and fewer pupae were recovered from wet than dry compost and soil. These results suggest that mulch material and/or moisture levels can have significant impacts on R. mendax pupation depth with potential implications for its management.

EFFECTS OF PINE-NEEDLE AND COMPOST MULCHES AND WEEDS ON NITROGEN DYNAMICS IN AN ORGANICALLY-MANAGED HIGHBUSH BLUEBERRY FIELD

Weed control is a major challenge for organic growers and nitrogen (N) fertility can be unpredictable when using organic amendments. A project assessing the use of heavy application of various mulches (pine needles and diverse composts) for organically-managed highbush blueberry (HBB) and their impact on weed growth and N acquisition, HBB growth, leaf tissue N, berry yield and quality, and soil acidity, moisture, temperature, and mineral N dynamics was initiated in 2005. From this, results for soil mineral N dynamics and plant and weed N removal are presented and discussed. The experiment was located in an established field of 'Duke' HBB in the Annapolis Valley, Nova Scotia, Canada. The design was a randomized split-plot consisting of five blocks, four fertility and mulch treatments [no amendment, pine-needle mulch (PN), manure-sawdust compost (MC) and seafood waste compost (SC)] as the main plots, and two levels of weed management (+/- hand-weeding) as the split plots. Residual ('carry-over') effects of mulches one year after application were also examined. Results from the 2-yr study indicate that weeds were a significant competitor for soil mineral N, reducing soil N content by 71%. In addition, weed competition was shown to reduce HBB growth and fruit yield. There was no evidence of net N immobilization despite high C/N ratios of the PN (72:1) and MC (48:1). Elevated soil mineral N levels were maintained for the longest period under SC, while PN did not increase mineral N above control levels. Pine-needle mulch was found to be the best treatment for suppressing weed competition, although additional N nutrition is warranted.

Evaluation of ultrasonic aggregate stability and rainfall erosion resistance of disturbed and amended soils in the Lake Tahoe Basin, USA

Application of organic soil amendments to disturbed soil has been shown to improve aggregate stability and reduce soil susceptibility to erosion. Employing ultrasonic aggregate stability assessment techniques described earlier [Fristensky, A. and Grismer, M.E., 2008. A simultaneous model for ultrasonic aggregate stability assessment. Catena, 74: 153–164.], we assess the effect of two experimental organic soil amendments – a compost and a woodchip mulch incorporated at a rate of 2000–6000 kg ha− 1 N-equivalence – on soil aggregation and aggregate stability at four drastically disturbed sites within the Lake Tahoe Basin, USA. Experimental plots were established 1–3 years prior to testing. The soils were of granitic or volcanic origin, and disturbed by either ski run or road development. Soil treatments were observed to significantly (p < 0.05) increase both aggregation (300% average increase) and ultrasonic aggregate stability (600% average increase) relative to the untreated soil. However, at the two sites disturbed by ski run development, the control treatment (tilling and surface application of pine–needle mulch) performed comparably to the two incorporated compost treatments, suggesting that the effects of the experimental amendments on aggregation were negligible at these sites, or their effective duration was shorter than the evaluation period. Rainfall simulations (72–120 mm h− 1) were performed on the treatment plots, and results were compared with the ultrasonic aggregate stability indices. Significant (p < 0.05) positive correlations were obtained between the measurements of aggregate instability and indices of soil susceptibility to runoff, including steady-state infiltration rate (measured values between 1 and 120 mm h− 1), and the level of kinetic energy of applied rainfall at which runoff commences (EBR, measured values between 12 and 224 J m− 2). However, no correlation was found between the ultrasonic aggregate stability indices and observed soil erosion variables. Interestingly, positive relationships (p < 0.05) were observed between both infiltration rate and EBR and the proportion of 2–20 μm and < 2 μm particles liberated from the largest aggregates detected in each soil. Our results suggest that ultrasonic aggregate stability indices may be useful indicators of soil susceptibility to runoff and erosion under rainfall.

Crescimento de plantas de mirtilo a partir de mudas micropropagadas

Mudas de mirtilo apresentam crescimento inicial lento e baixo índice de sobrevivência. Dentre os fatores envolvidos na produção de mudas, a qualidade do substrato é um fator de grande importância. O trabalho foi realizado com o objetivo de avaliar o desenvolvimento de mudas de mirtilo, em diferentes composições de substrato, durante os meses de dezembro de 2005 a março de 2006. Foram utilizadas mudas da cultivar Georgiagem, do grupo highbush, oriundas de multiplicação in vitro. Foram utilizados sete diferentes substratos para a formação das mudas: T1 - Plantmax® (100%); T2 - Plantmax® + perlita (1:1); T3 - solo + composto industrial + perlita (1:1:1); T4 - solo + casca de arroz + terra (1:1:2); T5 - solo + composto industrial + vermiculita (1:1:1); T6 - casca de acácia + terra (1:2); T7 - acícula de pínus + terra - (1:2). Foram avaliados: altura das plantas; acúmulo de matéria seca da parte aérea e raiz, e análise química dos substratos. A composição do substrato influenciou no desenvolvimento das mudas de mirtilo. Os melhores resultados foram observados em substratos com pH ácido. Conclui-se que os substratos acícula de pínus + terra, Plantmax®, Plantmax® + perlita e casca de arroz + terra apresentaram melhores resultados.

Trap-Mulching Argentine Ants

Argentine ant, Linepithema humile (Mayr), management is constrained, in large part, by polydomy where nestmates are distributed extensively across urban landscapes, particularly within mulch. Management with trap-mulching is a novel approach derived from trap-cropping where ants are repelled from a broad domain of nest sites to smaller defined areas, which are subsequently treated with insecticide. This concept was field-tested with mulch surrounding ornamental trees replaced with a narrow band of pine (Pinus spp.) needle mulch (trap) within a much larger patch of repellent aromatic cedar (Juniperus spp.) mulch. After ants reestablished around the trees, the pine needle mulch band was treated with 0.06% fipronil (Termidor). Poor results were obtained when the trap extended from the tree trunk to the edge of the mulched area. When the trap was applied as a circular band around the tree trunk reductions in the number of foraging ants were recorded through 14 d compared with an untreated mulch control, but not for longer periods. Reductions in the number of ant nests within mulch were no different between the trap mulch and any of the other treatments. We conclude that trap-mulching offers limited benefits, and that successful management of Argentine ants will require implementation of complementary or perhaps alternative strategies.

Erosion control reduces fine particles in runoff to Lake Tahoe

Sediment in hillslope runoff from disturbed soils in the Lake Tahoe Basin is the source of many fine suspended particles that transport nutrients and contribute to a loss in lake clarity. In previous studies, we used rainfall simulation to assess and quantify infiltration, runoff and erosion rates from hillslope soils. Building on this research, our current study evaluates the relationship between particle sizes in runoff sediments and slope, and compares the relationships between restored soil treatments and bare and undisturbed (native) forest soils. Soil restoration combined with pine needle mulch treatments substantially reduced sediment yields in runoff water, and increased the size of runoff particles when compared to that from bare soils. Very little, if any, runoff and erosion occurred from relatively undisturbed “native” soil plots at similar slopes.

Natural Mulches Are Not Very Effective for Weed Control in Onions

This study was undertaken to evaluate natural mulches for weed control in organic onion (Allium cepa) production where current practices rely on hand-weeding or plastic mulch. Three experiments were conducted over 2 years, with two experiments conducted on-farm in different years and one experiment conducted on-station. Treatments consisted of hand-weeding or mulches of wheat (Triticum aestivum) or oat (Avena sativa) straw, bermudagrass hay (Cynodon dactylon), compost, and needles of slash pine (Pinus elliottii) and longleaf pine (P. palustris). All of the mulches with the exception of compost tended to lodge in the onion tops due to their close spacing. Wheat straw and bermudagrass hay reduced plant stand and yield. Compost settled well around the onion plants and initially smothered weeds, but over time the compost treatment became very weedy. Pine needle mulch (referred to as pine straw in the southeastern U.S.) showed the most promise with less stand loss or yield reduction, but did tend to lodge in the tops. None of these mulches were acceptable compared to hand-weeding.