Evaluating the Effectiveness of Mulching for Reducing Soil Erosion in Cut Slope and Fill Slope of Forest Roads in Hyrcanian Forests

Forest operations often enhance runoff and soil loss in roads and skid trails, where cut slopes and fill slopes are the most important source of sediment. This study evaluated the effectiveness of four erosion control treatments applied to cut slope and fill slope segments of forest roads of different ages in the Hyrcanian forest in northern Iran. The treatment combinations, each replicated three times, included four classes of mulch cover (bare soil [BS], wood chips cover [WCH], sawdust cover [SC], and rice straw cover [RSC]), two levels of side slope (cut slope and fill slope), two levels of side slope gradient (20–25% and 40–45%), and three levels of road age (three, 10 and 20 years after construction). Mulch cover treatments significantly reduced average surface runoff volume and sediment yield compared to BS. Regardless of erosion control treatment, greater surface runoff volume and soil loss under natural rainfall occurred on steeper slope gradients in all road age classes and decreased with increasing road age on both slope gradients. On cut slopes, average runoff and soil loss from the plots covered with WCH (17.63 l per plot, 2.43 g m–2) was lower than from those covered with SC (22.81 l per plot, 3.50 g m–2), which was lower than from those covered with RSC (29.13 l per plot, 4.41 g m–2 and BS (34.61 l per plot, 4.94 g m–2). On fill slopes, average runoff and soil loss from the plots covered with WCH (14.13 l per plot, 1.99 g m–2) was lower than from plots covered with SC (20.01 l per plot, 3.23 g m–2), which was lower than from plots covered with RSC (24.52 l per plot, 4.06 g m–2) and BS (29.03 l per plot, 4.47 g m–2). Surface cover successfully controlled erosion losses following road construction, particularly on steep side slopes with high erosion potential.

Cattle Grazing Exclusion Increases Basal, Crown and Mulch Cover in the Sierra de Órganos National Park, Sombrerete, Zacatecas, Mexico

Objective: To estimate the effects of cattle grazing exclusion on soil and vegetation conditions in grasslands of Sierra de Órganos National Park (SONP), Sombrerete, Zacatecas, Mexico. Design/Methodology/Approach: Four transects with cattle grazing exclusion were strategically established in SONP grasslands. In each transect the basal, crown and organic mulch cover, soil cover, bare soil, and the form of the autumn plant were measured from 2008, 2010, 2012 and 2014. Results: Cattle grazing exclusion caused an increase in basal, crown and organic mulch cover, soil cover, as well as over- rested plants and deteriorated plants; bare soil cover and the percentage of normal plants decreased. Study Limitations/Implications: Increase of organic mulch cover implies the accumulation of combustible material that represents a potential risk of fire occurring in the SONP. Findings/Conclusions: Increase of organic mulch, over-rested plants and deteriorated plants shows that SONP grasslandsare transiting to a less stable ecological state.

DYNAMICS IN PHYSICOCHEMICAL PROPERTIES OF SOILS UNDER OIL PALM PLANTATIONS OF DIFFERENT AGES

Removing forest cover for oil palm plantations has raised questions about climate change problems and debates and their associated impacts. The design of the pruned fronds of the trees does not make them ideal for use as mulch cover on the entire farm, but they are heaped between the plant rows. This research investigated the changes in the physicochemical properties of soils under oil palm plantations of different ages. Soil surface (0-20 cm) and subsurface (20-40 cm) samples have been obtained from various ages of oil palm plantations (0-5, 5-10, 10-15 and, 15-20 years). Two distinct samples were taken on the same farm, under alleys and heaped pruned fronds. Soil samples used as a standard (control) were collected from adjacent forest land. Analyses of particle size showed that the soils were sandy loam to sandy clay loam texture soils. Bulk density was low and varied with age and depth. The soils were moderate to slightly acidic pH, relatively low organic carbon, total nitrogen, and available phosphorus contents. Based on the standard ratings, exchangeable bases and cation exchangeable capacity content were also low, while high percent base saturation was observed. Research findings have shown that the soil properties of different ages of oil palm plantations vary and should therefore be handled differently based on of their characteristics. Accumulation of organic residue on the floor of the plantations should be encouraged as this will help to increase organic matter levels.

Evaluating Mulch Cover with Coir Dust and Cover Crop with Palma Cactus as Soil and Water Conservation Techniques for Semiarid Environments: Laboratory Soil Flume Study under Simulated Rainfall

This paper aims to investigate the performance of mulch cover with coir dust (Cocos nucifera L.) and cover crop with Palma cactus (Opuntia ficus indica Mill.) as soil and water conservation techniques, in a laboratory soil flume under simulated rainfall. Palma cactus plants oriented at 90° and 30° angles with the slope direction were considered. Simulations comprised uniform advanced and delayed rainfall patterns. Runoff hydrographs and soil loss were monitored at the downstream end of the flume. Soil moisture and flow velocity were measured, and several hydraulic parameters of runoff were estimated. Results show that both mulch cover with coir dust and cover crop with Palma cactus were effective in reducing runoff and soil loss and increasing soil moisture content, thus being both suitable soil and water conservation techniques for semiarid environments. Coir dust was more effective than Palma cactus. Palma cactus oriented at a 90° angle was slightly more effective than Palma cactus oriented at a 30° angle. Differences between advanced and delayed rainfall patterns on the hydrological and erosive response were more pronounced for the mulch cover condition, where no runoff and soil loss were observed at the downstream end of the flume for the advanced rainfall pattern.

Sphagnum reintroduction under a warming climate: keys to success

<p>Restoring peatland functioning is closely related to restoring growth of ecosystem engineering Sphagnum species. In strongly degenerated peatlands reintroducing diaspores of Sphagnum is necessary to overcome strong dispersal and establishment bottlenecks. Which reintroduction strategy varies between peatland types, surface properties and/or microclimate. Comparative analyses of restoration techniques is scarce, hampering informed management choices.    </p><p>We set out to assess keys to success for Sphagnum reintroduction on strongly humified bare peat in three degraded and long-time rewetted temperate peatlands in the Netherlands. To this end we experimentally manipulated water table position (control, extra water), type of abiotic shelter (control, nurse plants, mulch), Sphagnum species (S. magellanicum, S. papillosum and S. cuspidatum), species mixture (monoculture, mixed culture), diaspore size (clumped intact plants or fragments) and diaspore density (0, 36, 72, 156 plants/m<sup>2</sup>) and monitored Sphagnum survival, lateral expansion and environmental conditions. The experiment was established in 2018 and repeated in 2019, covering two of the most extreme summers in recorded history.</p><p>Water table close to the surface and shelter of a mulch layer were key to Sphagnum survival and growth irrespective of Sphagnum species, reintroduction method or year. Survival increased linearly with diaspore density. Diaspore size showed an interaction with mulch cover: fragments did best under mulch cover, whereas clumped plants survived better outside shelter.</p><p>Taken together our results suggest that successful reintroduction of Sphagnum is possible under a warming climate, but that strategies should be strongly focussed on amelioration of abiotic stress even when water tables are close to the surface. </p>

Spatio Temporal Soil Moisture Dynamics and Runoff under Different Soil Cover Conditions in a Semiarid Representative Basin in Brazil

Hydrological studies in small basins are essential for investigating the role of distinct processes on water resources conservation and to assess the impact of the natural ecosystems on improving water security especially in semiarid environments. In Brazil, the cooperative hydrological Network REHISA (“REde de HIdrologia do SemiÁrido”) comprises hydrologists from several universities of Brazil, focusing on field measurements, monitoring and modeling activities in well instrumented experimental rural catchments located at different regions and biomes in Semiarid environment. Water scarcity is a common aspect among the catchments, as well as risks of soil and water degradation. The objective of this work is to present assessments of near surface soil moisture spatial-temporal distribution, and to evaluate the impact of soil conservation techniques in reducing runoff, using small-scale experimental plots in a representative catchment of the Pernambuco State, Brazil. The study catchment is located in Alto Ipanema River Basin (AIRB) (with an area of 150 km2), which is located at the semiarid region of the São Francisco River (area of 641 000 km2). Soil and water monitoring was performed in experimental plots with different soil cover conditions (Bare soil plots; Plots with natural cover – Caatinga Biome vegetation; Plots with cactus Palma barriers; and Plots with mulch cover – Dry grass mulch at 4 t ha−1), where probes were installed for high resolution soil moisture assessment. In addition, regular soil moisture monitoring campaigns were conducted at 7 different locations, using a capacitance probe, with arboreal and shrub Caatinga vegetation, pasture and bare soil, predominantly Brachiaria decumbens. Mulch cover runs close to the Caatinga cover, but still with higher runoff generation, and presenting lower soil moisture temporal mean values. Caatinga was highly effective in terms of soil and water conservation at the small basin scale for both the dry and the wet season, resulting in a positive nexus between vegetation and water availability at the region.

Chia (Salvia hispanica) experiment at a 30˚ N site in Sichuan Basin, China

ABSTRACT: The mysterious ancient Mesoamerican Indian crop chia (Salvia hispanica) is revived and expanding worldwide due to its richness of valuable nutraceuticals such as α-linolenic acid (ALA), antioxidants, food fiber, gels, and proteins. We carried out a pilot experiment on chia planting in non-frost Sichuan Basin, at Hechuan Base (30˚0′ 43″ N, 106˚7′ 41″ E, 216 m), Southwest University, Chongqing, China. The split-plot trial contained two factors, 3 spring-summer sowing times as main plots, and 6 densities as subplots, with 3 replicates. Phenological, botanical, adversity, yield, and seed quality traits were investigated. Plants were very tall, suffered from lodging, and flowered in mid-October. Sichuan Basin can be considered as a north edge for growing chia, with low yield (680 kg/hectare) because of insufficient seed filling and maturation in autumn-winter season (1000-seed weight of 1.14 g). However, its ALA content is 5 percent points higher than the seed-donor commercial bottle (65.06%/63.96% VS 59.35%/59.74% for black/white seeds), accompanied by decrease oleic and stearic acid, while linoleic acid and palmitic acid are equivalent. Considering its short-day habit, it is recommended to try sowing in middle summer (from late June to early August) to avoid too long growing period, excessive vegetative growth, and waste of field and climate resources caused by spring-summer sowing. Furthermore, winter sowing of chia with mulch cover could also be tried, with an expectation of harvesting in summer. Most importantly, only when the photoperiod-insensitive early flowering stocks are created, chia can be recommended as a low-risk crop to the farmers of this region.

EVAPOTRANSPIRAÇÃO E COEFICIENTE DE CULTIVO DO FEIJÃO-CAUPI CULTIVADO EM SOLO DO CERRADO SUBMETIDO À COBERTURA MORTA

EVAPOTRANSPIRAÇÃO E COEFICIENTE DE CULTIVO DO FEIJÃO-CAUPI CULTIVADO EM SOLO DO CERRADO SUBMETIDO À COBERTURA MORTA HIPÓLITO MURGA-ORRILLO1; WELLINGTON FARIAS ARAÚJO2; PAULO ROBERTO RIBEIRO ROCHA3; ROBERTO TADASHI SAKAZAKI4; LUIZ FERNANDES SILVA DIONISIO5 E ANA ROSA POLO-VARGAS6 1Engenheiro Agrônomo, Prof. Invitado, Universidad Nacional de Cajamarca, (UNC), Av. Atahualpa Nº 1050- Carretera Cajamarca-Baños del Inca, Cajamarca, Perú. [email protected] Agrônomo, Prof. Dr. Associado da UFRR/CCA, Boa Vista, RR. [email protected] Agrônomo, Prof. Adjunto da UFRR/CCA, Boa Vista, RR. [email protected] Agrônomo, Doutorando na UFRR/CCA, Boa Vista, RR. [email protected] Florestal, Doutorando na UFRA, Belém, PA. [email protected] Agrônomo, Graduada na UNC, Av. Atahualpa Nº 1050- Carretera Cajamarca-Baños del Inca, Cajamarca, Perú. [email protected] 1 RESUMO O conhecimento dos parâmetros hídricos de uma cultura é fundamental para o incremento da produtividade sem o desperdício de água. Objetivou-se com o presente trabalho determinar a evapotranspiração (ETc) e o coeficiente de cultivo (Kc) da cultura de feijão-caupi (Vigna unguiculata L.) cv. Novaera, em condições de solo com e sem o uso de cobertura morta. O experimento foi conduzido no campus Cauamé da Universidade Federal de Roraima, em Boa Vista, RR, entre os meses de abril a julho de 2014. A evapotranspiração de cultivo (ETc) foi obtida por meio de lisímetro de drenagem. Os resultados evidenciaram que a ETc do feijão-caupi para ciclo da cultura sem e com cobertura morta foram de 311,0 e 260,4 mm, com valores médios de 3,5 e 3,0 mm dia-1, respetivamente. O estádio fenológico de maior demanda hídrica foi o reprodutivo atingindo valores de 5,4 mm dia-1 em solo sem cobertura e 4,9 mm dia-1 em solo com cobertura. Os Kc's pelos estádios de desenvolvimento, inicial (I), crescimento (II), reprodutivo (III), e final (IV) pelo método de Penman-Monteith foram equivalentes à 0,42; 0,82; 1,60 e 0,79 em solo sem cobertura morta, e 0,30; 0,73; 1,46 e 0,56 em solo com cobertura morta. Semelhante, o método de Jensen-Haise apresentou valores de 0,38; 0,76; 1,31 e 0,61 em solo sem cobertura morta e 0,29; 0,67; 1,19 e 0,42 em solo com cobertura morta. Palavras-chave: Vigna unguiculata. Otimização de uso de água. Consumo hídrico. MURGA-ORRILLO, H.; ARAÚJO, W. F.; ROCHA, P. R. R.; SAKAZAKI, R. T.; DIONISIO, L. F. S; POLO-VARGAS, A. R.EVAPOTRANSPIRATION (ETc) AND CROP COEFFICIENT (Kc) OF COWPEA CROP IN SOIL WITH AND WITHOUT MULCH COVER IN THE RORAIMA SAVANNAH 2 ABSTRACT The determination of water parameters of a crop during its development is essential to maintain yield without wasting water. This study aimed to determine evapotranspiration (ETc) and crop coefficient (Kc) of cowpea crop (Vigna unguiculata L.) cv. Novaera during the various stages of development in soil conditions with and without mulch. The experiment was conducted in Cauamé, campus of the Federal University of Roraima, from April to July 2014, Boa Vista, Roraima state. Evapotranspiration cultivation (ETc) was obtained by drainage lysimeter, while the evapotranspiration reference (ETo) was estimated by Penman-Monteith and Jensen-Haise methods. The results determined that water consumption of cowpea in soil conditions with and without mulch were 311.0 and 260.4 mm, respectively. For Kc's developmental stages, initial (I), growth (II), reproductive (III), and final (IV), Penman-Monteith method showed values of 0.42, 0.82, 1.60, and 0.79 in soil without mulch, and 0.30, 0.73, 1.46, and 0.56 in soil with mulch, although the Jensen-Haise method showed values of 0.38, 0.76, 1.31 and 0.61 in soil with mulch and 0.29, 0.67, 1.19, and 0.42 in soil with mulch. Keywords: Vigna unguiculata. Optimization of water use. Water consumption