Amount Of Mulch Research Articles

Effect of no‐tillage on soil redistribution estimated by beryllium‐7, soil moisture, and carbon fractions loss in central Benin

AbstractSoil erosion has become one of the most common environmental problems and threatens food security. This study assessed the short‐term effect of tillage and mulch on soil redistribution using the beryllium‐7 method, soil moisture distribution, and soil organic carbon loss through soil erosion in typical agroecological conditions of Benin. The experiment was conducted on acrisols (at Dan) and ferralsols (at Za‐zounmè) in central Benin. Three tillage practices slope ridging (SR), contour ridging (CR), and no‐tillage (NT), and three mulch doses 0 (0 M), 3 (3 M), and 7 t ha−1 (7 M) on soil erosion under maize were investigated. The results showed a tillage and mulch interaction significantly (p < 0.05) influencing the soil redistribution, the loss of total carbon, the carbon of the particulate organic matter (C_POM), and the carbon content of the fine organic matter (C_MOM). High soil erosion was observed under SR0M (−10.19 t ha−1) at Dan and under NT0M (−7.36 t ha−1) at Za‐zounmè. NT7M (0.80 t ha−1), SR7M (0.69 t ha−1), CR3M (2.07 t ha−1), and CR7M (4.05 t ha−1) showed deposition at Dan, while SR7M (0.23 t ha−1), NT7M (1.69 t ha−1), and CR7M (3.93 t ha−1) showed deposition at Za‐zounmè. C_MOM was lost on both sites. Mulch increases soil moisture for all three tillage treatments, and this effect is well pronounced especially if the amount of mulch is great. This study revealed useful information to be taken into consideration when developing soil and water conservation management strategies in Benin.

Design and Experiment of Side-Shift Stubble Avoidance System for No-Till Wheat Seeder Based on Deviation-Perception Fusion Technology

To improve the stubble avoidance rate of no-till wheat seeders under the environment of corn stubble, the side-shift stubble avoidance system was developed in the present study based on deviation-perception fusion technology. Firstly, the amount of implement deviation compensation was accurately obtained by the information sensing system. Then, a fuzzy PID algorithm was proposed to optimize the performance of the control system. Finally, the simulation model of the control system was developed by Matlab/Simulink. The simulation results showed that the regulation time required for the system response curve to reach the steady state was 1.0 s, and the maximum overshoot was 8.2%. To verify the performance of the side-shift stubble avoidance system, an orthogonal test was conducted. The optimal combination of parameters was obtained, including the operation speed of 1.3 m/s, the hydraulic cylinder speed of 25 mm/s, and the straw mulch amount of 1.2 kg/m2. The field verification test was performed under the optimal parameters, showing the stubble avoidance rate was 90.6%, and the mean value of the sowing variation coefficient was 27.12%, which fully satisfied the requirements of stubble avoidance and sowing operation.

Farmers’ knowledge and adoption of improved mandarin orchard management practices in Syangja district, Nepal

Mandarin is one of the major fruit crops in the mid-hills of Nepal. Since improved farming practices appear to offer a significant chance to boost production and revenue, a study was conducted in Syangja, Nepal with the objective to assess farmers’ knowledge and adoption of improved mandarin orchard management practices and identify factors affecting their adoption. Primary data were collected by the use of pretested semi-structured questionnaire from randomly selected 97 respondents within the study area. Data were entered and analyzed using MS Excel, SPSS, and STATA, and the inferences were retrieved using the binary logistic regression model. Findings revealed that the respondents were familiar with most of the improved orchard management practices, however, there was variation in the scale of adoption of these practices. The majority (>90%) were found to practice pruning, FYM application, and weed control; however, there were relatively fewer adopters when it came to the use of Bordeaux paste (75.25%), chemical fertilizers (17.52%), mulching (57.74%), irrigation (44.33%), and soil testing and amendment (39.18%). The study showed that the adoption of Bordeaux paste and soil amendment differ significantly by gender (p=0.069 and p=0.041, respectively). Training has a positive impact on the use of Bordeaux paste (p=0.026), chemical fertilizers (p=0.075), and soil amendment practices (p=0.003). The usage of chemical fertilizers is more prevalent among people with formal education (p=0.075). Knowledge level also positively influences the adoption of mulching (p=0.014) and soil amendment practices (p=0.000). The number of trees is positively and significantly associated (p=0.008) with irrigation practice. It is recommended that expanding access to irrigation facilities and encouraging the use of the recommended amount of fertilizers, mulch, and Bordeaux paste must be prioritized in the study area.

Long‐term ground cover affects soil bacterial community and carbon metabolism in the Loess Plateau, China

AbstractFarmland mulching can maintain soil nutrients, which plays a positive role in agricultural planting in the arid area. However, the composition of the soil microbial community and the C cycle involved is unclear under farmland mulching. Based on the Changwu Agro‐Ecological Experiment Station, this study set up a long‐term positioning experiment to explore the effect on soil bacterial community structure and C metabolism capacity. In this study, we include five treatments: control uncovered (CK), plastic film mulching (PF), high amount of straw mulching carried out in July, August, and September every year (St90), low amount of straw mulch throughout the growth period (S45), and high amount of straw cover throughout the growth period (S90). We combined Illumina MiSeq sequencing and Biolog‐ECO technology to analyze the functional characterization of soil bacterial community composition in terms of C source metabolism. The results indicated that the soil bacteria showed a high degree of epistatic clustering, and the operational taxonomic unit numbers of soil bacteria decrease as St90, S45, PF, CK, and S90. Redundancy analysis showed that soil available P, NH4+–N, soil moisture content were the main environmental factors affecting bacterial community composition. Proteobacteria, Acidobacteria, and Actinobacteria are the main dominant flora in this area. Soil bacterial C metabolism was highest under PF treatment. Structural equation modeling (SEM) shows that surface cover has direct and indirect effects on bacterial C metabolism capacity and diversity through soil physicochemical properties. Reasonable mulching methods have a positive effect on the sustainable development of agro‐ecosystems in arid areas.

Effects of long-term no-tillage and stover mulching on maize yield and its stability.

Clarifying the differences of maize yield and its stability under long-term no-tillage with different stover mulching amounts can provide theoretical and technical supports for establishing and evaluating long-term conservation tillage pattern and promoting grain production. Based on a long-term conservation tillage field experiment in the mollisol area of Northeast China since 2007, we analyzed the interannual variation, variation coefficient and stability of maize yield during 2013 and 2019 across five treatments, i.e., no-tillage stover-free mulching (NT0), no-tillage with 33% stover mulching (NT33), no-tillage with 67% stover mulching (NT67) and no-tillage with 100% stover mulching (NT100), with the traditional ridge cropping (RT) as the control. The results showed that compared with RT, long-term no-tillage with stover mulching treatments could increase maize yield. NT100 had the highest increasing rate of 11.4%, followed by NT67 and NT0, with the increasing rate of 11.0% and 10.4%, respectively. Maize yield exhibited a nonlinear relationship with the amount of stover mulch. The variation coefficient of maize yield under multi-year no-tillage with different stover mulching could be sorted as NT67<RT<NT100<NT33<NT0, and the yield sustainability index was NT67>NT0>NT100>RT>NT33, indicating that NT67 treatment could significantly reduce the interannual fluctuation of maize yield and had better sustainability of yield. No-tillage stover mulching significantly increased soil total carbon and total nitrogen contents, which were significantly positively correlated with maize yield. In conclusion, compared with traditional tillage, no-tillage stover mulching could increase maize yield and soil carbon and nitrogen contents. Appropriate stover mulching (NT67)had the potential to improve the stability and sustainability of maize yield.

Floristic Composition and Litter Deposition in a Degraded Area and in Reforestation with &lt;i&gt;Eucalyptus&lt;/i&gt;

The present study aimed to verify the floristic composition in two distinct areas: reforestation with Eucalyptus and degraded area subjected to fire. Plots of 0.5 m x 0.5 m were demarcated, dis-tributed in transect in the two analyzed areas, were carried out. The analyzed aspects were the following: plant species variability, fresh mass, dry mass and litter. The results showed that the cultivation with eucalyptus was the one with the highest amount of plant species, reaching the number of 17 species, while in the degraded area 11 different species were found. In terms of fresh and dry mass, there was no observed difference between areas. In relation to litter, the cul-tivation with eucalyptus had the highest weight. It is concluded that the cultivation with euca-lyptus showed the highest number of plant species, the highest amount of mulch and green mass; as for the dry mass, there was an equivalence in the results of the two areas.

Abundance, biomass and community composition of soil saprophagous macrofauna in conventional and organic sugarcane fields

Tropical island saprophagous invertebrates have received little attention despite their important role in sustaining soil fertility. Soil biodiversity in the agroecosystems of the Lesser Antilles is subject to various anthropic and environmental perturbations; therefore, it is crucial to promote agricultural practices that help preserve it. Here, we investigate the effect of conversion to organic farming in sugarcane production on soil saprophagous invertebrates in a Martinique plantation (Lesser Antilles). The abundance, biomass and diversity of communities were measured in three fields undergoing organic conversion and in two control fields under conventional production. Invertebrates were sampled both by pitfall trapping and Tullgren extraction. The results indicated that abundance was significantly higher in fields undergoing conversion (342 ± 78 ind.m−2) compared to fields under conventional farming (146 ± 34 ind.m−2). The response of the whole community's biomass to organic conversion was not significant, reflecting a contrasting response of each invertebrate taxa: isopod biomass was the most impacted, earthworm biomass was moderately impacted and diplopod biomass was not significantly affected. A total of 25 morphospecies for all taxa were distinguished in this study. However, the diversity did not differ and community composition remained similar under both farming practices. The response of invertebrate abundance and biomass could be either due to the direct toxicity of herbicides intensively used in conventional sugarcane cultivation or to the indirect effects of herbicides modifying micro-habitat parameters (weed biomass, amount of mulch and litter humidity). In conclusion, the study shows that organic farming has a beneficial effect on soil saprophagous invertebrates even after a short period of conversion (between one and two years), which is promising for restoring soil biological processes in the context of agroecological transition.

Life cycle assessment of mulch use on Okanagan apple orchards: Part 2 - Consequential

Wood and bark chip mulch has been shown to reduce net orchard greenhouse gas (GHG) emissions on an Okanagan Valley (British Columbia, Canada) apple orchard. However, this benefit was shown to be outweighed by the (attributional) life cycle impacts associated with mulch production. The current study expanded the scope of prior investigations to perform a consequential life cycle assessment of the impacts of increasing wood chip/bark mulch use in the production of apples on Okanagan orchards. This assessment included the impacts of the orchard system as well as other current alternative uses of wood chip/bark mulch which included bioenergy production and paper manufacturing. Many environmental impact categories were examined including human toxicity, freshwater aquatic ecotoxicity, depletion of abiotic resources (elements, ultimate reserves), photochemical oxidation, ozone layer depletion, terrestrial ecotoxicity, acidification potential, climate change, eutrophication, land use – land competition, and energy use (including non-renewable: fossil, nuclear, primary forest; and renewable: biomass, geothermal, solar, water and wind). One scenario was modelled to represent the case in which no mulch was used on orchards (only used for alternative products). A second model was created to represent the marginal impacts of adding the amount of mulch to an apple orchard necessary to produce 1 kg of apples (0.575 kg bark and 0.144 kg wood chips). These amounts of bark and wood chips were assumed to be taken away from their current alternative uses (co-generation for bark and paper production for wood chips), thereby decreasing the amount of electricity and heat produced by bark by 0.653 kWh electricity and 0.653 MJ heat, and the amount of paper produced by wood chips by 0.144 kg paper. In turn, these amounts of electricity, heat and paper were assumed to be produced by their marginal production technologies – hydro-electric generation for electricity, natural gas for heat, and recycled paper for paper production. Finally, the scenarios were modelled assuming the marginal market for co-generation from bark was in Washington, USA rather than the Okanagan, as a sensitivity analysis.The results did not show a clear environmental benefit to either using or not using mulch on orchards. In the scenario in which bark mulch was assumed to be used either on apple orchards or for co-generation in British Columbia, impacts in 14 categories (including climate change, eutrophication, acidification, all toxicities, land use and some renewable energy use) were lower when mulch was used on the orchard, and results for 5 categories (including some non-renewable and renewable resources/energy use) were higher. When bark mulch was assumed to be used either on orchards or for co-generation in Washington, terrestrial ecotoxicity, land use, biomass and solar energy use were lower when mulch was used on the orchard, and all others (15 categories) were higher. There was a large amount of uncertainty in the model, coming from data variability, data quality and impact assessment uncertainty. Overall, the orchard system played a significant role in the impact assessment results, and was the main contributor to the overall uncertainty. Based on these results, mulch use on orchards cannot be recommended to reduce environmental impacts, but the marginal impacts of using mulch warrant further investigation.

Potential use of fresh mulch to curb potato late blight epidemics in Brazil

ABSTRACT Field experiments were conducted during spring 2014 and fall and spring 2015 to determine the effect of fresh mulch on the development of Phytophthora infestans epidemics, in Lapa Municipality, Parana State, southern Brazil. The used cultivars were ‘Agata’, susceptible, and ‘BRS Ana’, moderately susceptible. The main treatment consisted in manually applying a 10cm-thick layer of fresh mulch when potato sprouts were emerging. Fresh mulch was prepared with plants available at that time of the year. For the spring experiments, fresh mulch was a mixture of oats, rye grass and wild radish (60 t/ha) and for the fall experiment, semi-ripe elephant grass (90 t/ha). Plots consisted of six 10m-long rows, spaced at 0.8m, containing 28 plants per row. Experimental design was in completely randomized blocks with four replicates. Natural inoculum was adopted. Percentage of leaf area was weekly estimated until the end of the plant cycle and the area under the disease progress curve (AUDPC) was calculated. Application of fresh mulch significantly reduced AUDPC by 32.1%, 12.4% and 23.1%, compared to control in all seasons, for ‘BRS Ana’ and by 26.1%, 2.8% and 12.0% for ‘Agata’. Application of fresh mulch showed to be a promising practice for the integrated management of late blight and for the protection of yields, especially in periods more favorable to the development of the disease. More detailed studies should be conducted on the plant type and amount of fresh mulch to be used, as well as on the possibility of reducing concentrations or increasing intervals between fungicide sprays.

Straw Removal Effects on Sugarcane Root System and Stalk Yield

The sugarcane (Saccharum spp. L.) mechanical harvesting system leaves a large amount of straw mulch on the soil surface. The straw mulch may affect soil conditions, root regrowth, and sugarcane yield. Thus, this study assessed the response of sugarcane root system growth and stalk yield to different rates of straw removal. An experiment was conducted in a Rhodic Kandiudox with sand clay loam texture to test the impact of four rates of straw removal: no removal (18.9 Mg ha−1 of dry mass); moderate removal (8.7 Mg ha−1); high removal (4.2 Mg ha−1) and total removal on sugarcane root system and stalk yield. Higher concentrations of roots (60%) were found in the first 40 cm of soil. Moderate straw removal resulted in higher root mass (3.6 Mg ha−1) and stalk production (23 Mg ha−1 of dry mass). However, no straw removal reduced root mass by &lt;40% (2099 kg ha−1) and reduced stalk yield by &gt;20% (105 Mg ha−1). Through regression analysis, it was estimated that retaining between 8.5 and 13 Mg ha−1 of straw resulted in the highest root mass and stalk yield. Managing straw removal to retain a moderate amount enables producers to sustain suitable soil conditions for sugarcane root growth and stalk production while providing straw for industrial use.

English

Soil quality constitutes a major factor for crops growth. This study aimed at determining the sustainable soil conservation practices that would increase maize growth as well as production and improve the soil moisture. Two experimental sites were chosen: Dan localized on Acrisol and Za- zounm&egrave; localized on ferralsol. Two cropping seasons were investigated: the long rain seasons of 2018 and 2019. The experimental design was split-plot with four replications. The main factor was tillage with three modalities: no-tillage (NT); ridging parallel to the slope (PR); Isohypse ridging (IR) and the second factor was mulching with four amounts: 0, 3, 5 and 7 t.ha-1. Tillage, mulch amount and their interaction significantly influenced the soil moisture, maize growth and yield over the two investigated cropping seasons at both sites whereby the highest values were obtained under IR for tillage, 7 t.ha-1 (for mulch amount) and IR7M (for the interaction tillage x mulch amount). Overall, IR significantly increased the maize growth speed by 8% at Dan and by 16% at Za-zounm&egrave;; the maize grain yield by 33% at Dan and by 30% at Za-zounm&egrave; and the soil water content by 24% at Dan and 20% at Za-zounm&egrave;, in comparison with No-Tillage. An increasing effect of mulch amount was also observed. As far as mulching is concerned, the highest values (in average of LR2018 and LR2019) of growth speed (3.77 cm.day-1 at Dan and 4.08 cm.day-1 at Za-zounm&egrave;); grain yield (3003.03 at Dan and 3471.09 kg.ha-1 at Za-zounm&egrave;) and soil water content (26.89 mm at Dan and 20.44 mm at Za-zounm&egrave;) were observed. This suggests that isohypse ridging associated with an appropriate amount of organic&nbsp; mulch could be&nbsp; an&nbsp; option&nbsp; to mitigate dry spells and drought and improve local farmers&rsquo; income in the area of low rainfall in sub- Sahara Africa. &nbsp; Key words: Crop residues, tillage practices, conservation agriculture, food security, watershed of Zou. &nbsp

Sampling and degradation of biodegradable plastic and paper mulches in field after tillage incorporation

Plastic biodegradable mulch (plastic BDM) is tilled after use, but there is concern about incomplete degradation and potential impact on subsequent crops, and we lack a reliable method to measure mulch degradation post soil-incorporation. We conducted two field experiments to (i) develop a sampling method to estimate the amount of mulch (fragments size >2.36 mm) in the field post soil-incorporation, and (ii) assess the amount of BDM in the soil after four consecutive years of mulch incorporation. In Expt. 1, we used the quartering method to reduce soil from a 1 m2 field sample area to a representative 19 L sample. In Expt. 2, we applied and tilled four plastic BDMs: BioAgri, Naturecycle, Organix AG, and an experimental mulch; and one paper mulch, WeedGuardPlus, in their respective plots for four consecutive years. Starting in year 2, we sampled soil with the quartering method each spring and fall to determine mulch recovery. With respect to the total amount of mulch applied, average mulch recovery in the fall for the three commercial plastic BDMs was 71%, 50%, and 35% after second, third and fourth applications, respectively. For the experimental mulch, the average recovery was 80%, 69%, and 54% in the fall after second, third, and fourth applications, respectively. Recovery was slightly lower in spring than in preceding fall all years. For WeedGuardPlus, average recovery was 14%–20% in each fall, and no recovery in any spring (complete degradation). The results show that the quartering method reliably estimates the amount of mulch in a field and BDMs degrade over time in the field even with repeated applications, but complete degradation takes >1 year. While a few standards (e.g., ASTM D5988) specify how to determine biodegradation of plastics in soil under controlled laboratory conditions, our sampling method assesses plastic degradation under diverse field conditions.

Mulching effects on soil nutrient levels and yield in coffee farming systems in Rwanda

AbstractDifferent combinations of organic mulch were applied in smallholder coffee farming systems to assess their effects on soil nutrient contents and coffee yield at three sites in different agro‐ecological zones in Rwanda. Mulching systems consisted of Cymbopogon spp. (T1), Panicum spp. (T2), Cymbopogon spp. and Panicum spp. (T3), Eucalyptus spp. and Cymbopogon spp. (T4), mixed residues (T5) and un‐mulched coffee used as control (T6). Mulch had significant and specific effects at each site (p &lt; 0.001). T3 reduced soil pH value and exchangeable acidity at Kibirizi, while at Karongi and Ruli, these effects were observed with T4 and T5. T4 and T5 significantly increased the content of soil carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg). The amount of nutrients released was regulated by the amount and type of mulch applied, the agro‐ecological conditions and the soil properties at each site. The increased soil nutrient levels led to improved soil fertility conditions and increased coffee yields. The coffee yields were significantly increased with T1 at Karongi (p &lt; 0.05) by up to 1.9 t ha−1. T2 and T3 had significantly higher yields at Kibirizi. Yields at Kibirizi were 48% lower compared to yields at Karongi; at this site, T1, T2, T3, T4 and T5 increased yields by 57%, 26%, 31%, 20% and 28%, respectively, when compared to the no mulching treatment (T6). However, coffee yields over 1.9 t ha−1 can only be obtained with additional applications of inorganic fertilizer at different rates depending on the agro‐ecological zone and soil type.

Application of N Fertilizer to Sugarcane Mulches: Consequences for the Dynamics of Mulch Decomposition and CO2 and N2O Fluxes

Using organic fertilizers on sugarcane mulches is a potentially interesting substitute for mineral fertilization in terms of economic and environmental impacts. However, no general agreement exists regarding the short-term effect of combining mulching and organic fertilization on greenhouse gas (GHG) emissions. Therefore, we studied different mixtures in the field by combining two amounts of sugarcane mulch (5 and 10 Mg ha−1) with different N fertilizers (urea, pig slurry, and digested sewage sludge). We measured CO2 and N2O emissions shortly after application of the mixtures (0–14 days) and the mulch decomposition dynamics from 0 to 120 days after application. We hypothesized that the relative amount of N to C modifies the decomposition dynamics and GHG fluxes. The emitted N2O-N and CO2-C were measured using static chambers. Mulch-C decomposition was measured using litterbags. Our results showed that the proportion of mulch-C remaining on the soil on day 120 was not altered by either the type of N fertilizer or the mulch amount. On a shorter time scale (0–49 days), the different N treatments affected the mulch-C and mulch-N losses and the C:N ratios, indicating a transient interaction between the dynamics of the mulch and the added N. The intensity of N2O-N emission was ranked as pig slurry > urea > digested sewage sludge, underscoring the effect of the physical form of N fertilizer. This work highlights the need to jointly study carbon and nitrogen dynamics and consider both soil carbon and gas emissions to assess the GHG balances of sugarcane farming practices.

Response of common cocklebur (Xanthium strumarium L.) emergence and competition with corn (Zea mays L.) to seed burial depth and mulch

ABSTRACTCommon cocklebur (Xanthium strumarium L.) is a summer annual weed of the corn fields in the north-western parts of Iran. Field experiments were conducted in 2013 and 2014 to examine the seedling emergence and growth of common at different achene (seed) burial depths (3, 6, 9, 12, 15 and 18 cm) and wheat straw mulch amounts (0, 1.5, 3.0 and 4.5 ton ha-1). Results indicated that increasing achene burial depth and mulch amount reduced X. strumarium seedling emergence. In both years, no seedling emergence was observed from 18-cm achene burial depth. X. strumarium biomass and achene number per plant were affected by achene burial depth and mulch amount, and were greater in 2014 than in 2013. The corn leaf area index (LAI) and grain yield were higher in the treatments which deeper achene burial depth and mulch amount were high. Therefore, X. strumarium emergence in the corn can be suppressed by a tillage that buries the achenes to ≥18 cm of soil depth. Maintaining a thick residue cover will provide competitive advantage of corn over X. strumarium due to an inhibitory effect on X. strumarium emergence and growth and may lead to a reduction in the future weed infestation.

English

Smallholder farmers in sub-Saharan Africa (SSA) are under increasing pressure due in part to climate change and soil degradation, with many farming households unable to achieve even basic food self-sufficiency. Conservation Agriculture (CA) is a possible solution to these challenges, but the lack of sufficient biomass for mulch has limited wide-scale adoption, and many farmers who practice CA resort to adding supplemental mulch to their CA plots. Legume intercropping would not only provide biological and nutritional diversity, it may also provide an in situ cover, thereby reducing the amount of mulch required for soil and water conservation. Farmer managed research experiments were used in two semi-arid areas of Zimbabwe to test whether intercropping a cereal crop [maize (Zea mays)] with a legume [cowpeas (Vigna unguiculata), lablab (Lablab purpureus) or pigeon pea (Cajanus cajan)] could increase the total amount of biomass produced. The experimental design included two replicates with legume species and presence or absence of mulch cover as factors in the design. Maize yields were increased more by adding mulch than by legume intercrops in the absence of mulch. Therefore, intercrops were not a substitute for mulch. However, adding intercrops did significantly increase the amount of total biomass (maize and intercrop dry matter) produced at the sites and therefore, in addition to contributing protein rich grains, intercrops may reduce the amount of mulch required for soil and water conservation in CA systems. Farmer participation allowed the research to be conducted in the context of small-holder CA. Key words: Intercropping, cowpea, lablab, pigeon pea, soil conservation, farmer-based research. &nbsp

The effectiveness of two contrasting mulch application rates to reduce post-fire erosion in a Portuguese eucalypt plantation

Wildfires are well-known to increase runoff and erosion during the initial stages of the window-of-disturbance, and mulching has been widely documented to effectively minimize this impact. However, the relationship between the rate of mulch application and erosion reduction is poorly studied, in spite of its potential importance for optimizing mulching costs and efforts per ha. Therefore, a field experiment was carried out in a recently burnt eucalypt plantation in Central Portugal that had been burnt by a moderate severity fire during August 2015, comparing sediment as well as organic matter losses from three untreated 2 m × 8 m erosion plots with losses from six plots mulched with eucalypt logging residues at two contrasting rates of either 2.6 or 8.0 Mg ha–1. The two mulching treatments resulted in the targeted litter covers of 50 and 79%, and these covers hardly changed over the ensuing year. Over this first post-fire year, the mulched plots produced significantly less mineral soil as well as organic matter losses than the untreated plots. At the same time, the plots with the high mulching rate lost consistently less sediments and organic matter than the plots with the low mulching rate but the differences were not statistically significant over all measurement periods. Total sediment losses over the first post-fire year were, on average, 86 and 96% lower following mulching at 2.6 and 8.0 Mg ha–1, respectively, than without mulching. In absolute values, total losses dropped from 8.0 to 1.1 and 0.3 Mg ha–1 y–1, respectively, or, in other words, similar to and well-below the widely-accepted threshold of tolerable soil loss of 1 Mg ha–1 y–1. If this threshold value is acceptable to land managers, they could treat a three times larger area with the same amount of mulch.

Effects of straw mulching on soil evaporation during the soil thawing period in a cold region in northeastern China

To study the effect of straw mulching on soil water evaporation, it is necessary to measure soil water evaporation under different conditions of straw mulching during the soil thawing period. A field experiment was conducted in winter, and soil evaporation was measured using a microlysimeter on bare land (LD) and 4500 (GF4500), 9000 (GF9000) and 13500 $$\hbox {kg/hm}^{2}$$ (GF13500) straw mulch. The influence of different quantities of straw mulch on soil water evaporation during the thawing period was analyzed using the Mallat algorithm, statistical analysis and information cost function. The results showed that straw mulching could delay the thawing of the surface soil by 3–6 d, decrease the speed at which the surface soil thaws by 0.40–0.80 cm/d, delay the peak soil liquid water content, increase the soil liquid water content, reduce the cumulative evaporation by 2.70–7.40 mm in the thawing period, increase the range of soil evaporation by 0.04–0.10 mm in the early stage of the thawing period, and reduce the range of soil evaporation by 0.25–0.90 mm in the late stage of the thawing period. Straw mulching could reduce the range of and variation in soil evaporation and can reduce the effect of random factors on soil evaporation. When the amount of straw mulch exceeded 9000 $$\hbox {kg/hm}^{2}$$ , the effect of increasing the amount of straw mulch on daily soil water evaporation was small.

Does straw mulch partial-removal from soil interfere in yield and industrial quality sugarcane? A long term study

Sugarcane straw mulch left in the field after its mechanical harvest has become very valuable raw material for second generation ethanol and bioelectricity production. However, little information is available on how much straw mulch is needed to be left in the field so that agricultural productivity is not affected and high sustainability is provided for the bioenergy production system. The objective of this work was to evaluate the productivity and industrial quality of sugarcane after five years of cultivation when different amount of straw mulch is removed from the field. The experiment was installed in clay texture Eutroferric Red Latosol (Oxisol). Six treatments were evaluated: 0%, 25% (5tha−1), 50% (10tha−1), 75% (15tha−1), 100% (20tha−1) of straw mulch and burnt cane harvesting (where 100% of the straw mulch was burned). Evaluated parameters included sugarcane productivity (tons/hectare) and its industrial quality (Pol, soluble solids (°Brix), apparent purity and total sugars (TS)). Productivity was calculated at the end of the cycle whereas industrial quality parameters were evaluated during three phases i.e. 180, 240 and 350days after cutting (DAC). Straw mulch of 50 and 75% were statistically at par with each other but resulted in higher sugarcane production with 47% more productivity as compared to 0 and 25% of straw mulch as well as burned cane harvesting. Straw mulch didn’t affect the industrial quality; however, higher sugar production was supported by higher agricultural productivity, under low moisture condition. It is possible to remove 50% of straw mulch from the field for the production of second generation ethanol or bioelectricity, without any damage to the crop.

Reliability of Soil Sampling Method to Assess Visible Biodegradable Mulch Fragments Remaining in the Field after Soil Incorporation

Biodegradable mulches (BDMs) provide a unique advantage to growers in that they can be tilled into the soil after use, eliminating disposal costs that include time, labor, and equipment needs. Biodegradation of BDMs in the soil can be assessed by the presence of visible mulch fragments; although this is not a direct measure of biodegradation, it provides an initial estimation of mulch biodegradation. We carried out three field experiments to develop a protocol for quantifying BDM fragments in the soil after soil incorporation of mulch. Expt. 1 was done at Mount Vernon, WA, and Knoxville, TN, using five BDMs in four replications, including a polyethylene (PE) mulch reference treatment (three replications and at Mount Vernon only), and a ʽCinnamon Girl’ pumpkin (Cucurbita pepo) test crop. At the end of the growing season, mulches were tilled into the soil to a depth of 6 inches and within 16 days, five soil samples were collected with a golf hole cutter (4 inches diameter and 6 inches deep). Fifty-nine percent of the PE mulch fragments were recovered from the reference treatment. Among the remaining treatments, there was a high plot-to-plot variation as to the percent of the BDM recovered (3% to 95% at Mount Vernon, 2% to 88% at Knoxville). To exclude the possibility of mulch degradation impacting mulch recovery, in Expts. 2 and 3 (at Mount Vernon only), one BDM was laid, then tilled into the soil and sampled using the same sampling core as in Expt. 1, but all in 1 day. In Expt. 2, 15 soil samples were collected per plot, which recovered 70% of the mulch, and in Expt. 3, the entire plot was sampled by collecting 128 soil samples per plot, which recovered 62% of the mulch. In summary, sampling with a relatively large core recovered less than 70% of tilled-in mulch, there was high variability between plots within each treatment because of uneven distribution of the mulch fragments in the plot, and even 50 samples per plot did not provide an accurate estimate of the amount of mulch remaining in the field. Thus, soil sampling with a large core was ineffective, and new sampling methods are needed to assess the amount of BDM remaining in the field after soil incorporation.