Comparison of the physical properties of vermicompost from paper mill sludge and green compost as substitutes for peat-based potting media

The properties of vermicompost, green compost, and their mixes as substitutes for peat were evaluated regarding their recommendation for potting media. The mixes with a maximum of 50% of vermicompost or green compost had acceptable air filled porosity (AFP) and easily available water (EAW). In the vermicompost the level of organic matter (OM), dry bulk density (DBD) and shrinkage were acceptable; however, the AFP and EAW together were not at the recommended level in the different batches; as a consequence, vermicompost should not be used alone for potting media. In the green compost, the level of OM was low which increased the DBD and consequently the AFP was diminished. The particle size distribution (PSD) was different among peat, vermicompost and green compost. The coarse peat had the lower proportion of particles from 0.25 to 2.00 mm (41%) whereas the green compost had the lower coarseness index (CI: percentage by weight of particles larger than 0.5 mm in diameter), 48.4%. The direct effect of the PSD, OM and DBD in the water and air availability was confirmed. Moreover, there were high correlations between the OM, DBD, shrinkage, pore volume and PSD with the water release curve. Those properties should be considered in order to increase the level of substitution of vermicompost in peat-based potting media

QUALITY IMPROVEMENT OF ORGANIC COMPOST USING GREEN BIOMASS

An experimental study following the completely randomized design (CRD) was conducted to address the low nutrient content of compost product from crop residues. Rice straw and corn stalks which were the locally available crop residue were used as the main compost material, while succulent stems plus green leaves of Ipil-ipil (Leucaena leucocephala) and wild sunflower (Tithonia diversifolia) were used as the green biomass material. Treatments were crop residue and green biomass combinations at 3:0, 3:1, 3:2 and 3:3 ratios subjected to rapid composting method with the aid of Trichoderma harziamum as activator. Using the compost products mixed with pure soil at 1:1 ratio, pot experiment was conducted to test the effect of green biomass-enriched compost on the early growth of eggplant (Solanum melongena) and green pepper (Capsicum annuum). The results indicated that, gradual enrichment of crop residue compost with green biomass especially those prepared at 3:3 and 3:2 crop residue-green biomass combinations gave significant increase in the Nitrogen, Phosphorous and Potassium contents of the compost. It also showed significant improvement on the percent organic matter, pH level, and weight of the compost product. The results further revealed that the use of green biomass-enriched crop residue compost significantly stimulated plant growth in terms of plant height, number of leaves, size of leaves, number of buds, and total weight of fresh plant biomass. The overall findings of the study indicated that gradual application of green biomass during composting of crop residue produced better quality of compost that can be used to stimulate plant growth

Effects of organic fertilisers and compost extracts on organic tomato production

The effects of various fertilizers and different compost extracts on crop health and tomato yield were studied in the field in 2004–2005 in two locations in Iran. Treatments included different fertilizers (cattle, sheep and chicken manures, green waste and household composts and chemical fertilizers) and five aqueous extracts (from cattle manure, chicken manure, green-waste and house-hold composts and water as control). The effect of fertilizer type on tomato yield was significant in both locations (P < 0.05). Organic fertilizer use did not obtain higher yields compared to using chemical fertiliser. Generally, chicken manure and green-waste compost led to the highest and lowest tomato yield among different organic fertilizers, respectively. The effect of aqueous extracts was not significant on either crop health or tomato yield with these results were being very limited and inconsistent. Improved efficacy of acceptable alternatives to agrochemicals, especially in organic farming, is required

Management & sustainability of stockless organic arable and horticultural systems

The essential difference between stockless and stocked systems is that the fertility building clover ley and other “forage crops” are not processed through an animal but instead are grown as green manures which are returned directly to the soil by mulching, incorporation or occasionally through composting of the green manure. Stockless systems provide no opportunity for the creation of straw and animal manure based farm yard manure or compost. While there is no research evidence that the lack of animals or manure based compost affects overall soil fertility and crop yield, there is some research evidence that animal manure enhances soil mychorrizae populations and soil organic matter accumulation. This effect might also be seen from the use of plant based compost, sometimes sourced off-farm as “green waste” in stockless systems, but there is no comparative work available. While the use of manures has the advantage of allowing movement of fertility around the farm within a rotation, grazing animals have the drawback of uneven dispersal of manure and urine and manure storage is liable to poor management and loss of nutrients. Green manures are fundamental to stockless systems, both as one or two year crops which are either mulched or incorporated or grown as short term catch crops or undersown crops. With appropriate selection and management of green manures there is potential for enhanced fertility building over that which is possible with grazed leys. The practical commercial experience of farmers using stockless rotations is stronger than the research would suggest in terms of supporting its technical success and viability. Weed control remains a serious problem for arable farms which requires very high standards of management. The demand for organic livestock products is increasing and the area of organic land producing feed grains is insufficient to support the required expansion. World demand for organic grains is increasing. The introduction of livestock on to specialist conventional cereal producing farms in many instances requires prohibitively expensive infrastructure costs. Stockless rotations utilising green manures to fix nitrogen as part of the rotation provide a technically feasible and profitable alternative. Stockless horticultural systems operated with or without the use of imported manure or compost offer potential for technically and financially viable systems provided that there is an appropriate balance of fertility building green manures and cash crops

Effect of Urea and Cow Fecal Compost on Growth and Yield of Green Eggplant (Solanum melongena L.)

Eggplant (Solanum melongena L.) is a vegetable that grows well in various regions in Indonesia. Its growth is largely determined by the availability of nutrients in agricultural land. Research has been conducted on the effect of urea and cow fecal compost on the growth and yield of green fighting plants. This study aims to determine: (1) the effect of urea application on the growth and yield of green eggplant plants, (2) the effect of cow fecal compost application on the growth and yield of green eggplant plants, (3) the effect of the interaction of urea and cow fecal compost. on the growth and yield of green eggplant plants. This study used a 2-factor design. The first factor is the dose of urea fertilizer and the second factor is the dose of cow fecal compost. Growth parameters were stem height, leaf length, and leaf width, while yield parameters were the wet weight of green eggplant. The research data were analyzed using analysis of variance. The results showed: (1) differences in the dose of cow fecal compost had a significant effect on stem height, leaf length, and fruit wet weight but had no significant effect on leaf width of green eggplant, (2) differences in the dose of urea had a significant effect on the stem, leaf length, and leaf length and fruit wet weight but did not significantly affect leaf width of green eggplant, (3) the interaction between urea fertilizer treatment and cow compost did not significantly affect all growth parameters and yield parameters of green eggplan

Application of COMPOCHIP Microarray to Investigate the Bacterial Communities of Different Composts

A microarray spotted with 369 different 16S rRNA gene probes specific to microorganisms involved in the degradation process of organic waste during composting was developed. The microarray was tested with pure cultures, and of the 30,258 individual probe-target hybridization reactions performed, there were only 188 false positive (0.62%) and 22 false negative signals (0.07%). Labeled target DNA was prepared by polymerase chain reaction amplification of 16S rRNA genes using a Cy5-labeled universal bacterial forward primer and a universal reverse primer. The COMPOCHIP microarray was applied to three different compost types (green compost, manure mix compost, and anaerobic digestate compost) of different maturity (2, 8, and 16 weeks), and differences in the microorganisms in the three compost types and maturity stages were observed. Multivariate analysis showed that the bacterial composition of the three composts was different at the beginning of the composting process and became more similar upon maturation. Certain probes (targeting Sphingobacterium, Actinomyces, Xylella/Xanthomonas/ Stenotrophomonas, Microbacterium, Verrucomicrobia, Planctomycetes, Low G + C and Alphaproteobacteria) were more influential in discriminating between different composts. Results from denaturing gradient gel electrophoresis supported those of microarray analysis. This study showed that the COMPOCHIP array is a suitable tool to study bacterial communities in composts

Physiological responses of growth and production of baby corn (Zea mays Saccharata L.) due to application of agricultural waste based compost and NPK fertilizer

A trial was conducted to study the physiological responses of baby corn to changes in soil fertility by application of organic and inorganic fertilizers.  The research was conducted at the Teaching Farm, Faculty of Agriculture, Universitas Hasanuddin from May to August 2020. The experiment was arranged based on a factorial randomized block design (RBD) with two factors repeated 3 times. The first factor is the dosage of green compost consisted of four levels, namely 0, 3, 4, and 5 tons ha-1. The second factor was the percentage of NPK fertilization from the recommendations consisted of four levels, namely NPK 100%, 75%, 50%, and 25%. The results show that the treatment of 4 ton ha-1 of green compost resulted in the highest absorption rate of CO2 (336.2 µmol CO2 mol-1) and the highest humidity level (68.8%). 100% NPK fertilizer treatment showed the highest CO2 absorption rate (338.1 µmol CO2 mol-1), the highest leaf photosynthesis rate (36.1 µmol CO2m-2s-1). The treatment of 5 ton ha-1 of green compost and 100% NPK fertilizer resulted in the lowest transpiration rate (0.20 liters m-2s-1). The treatment of 3 ton ha-1 green compost and 100% NPK fertilizer resulted in earlier flowering age (46.3 days) and heaviest ear weight (63.67 g). The treatment of 5 ton ha-1 green compost with 50% NPK fertilizer resulted in the longest ear length with husk (21.72 cm). Treatment of 4 ton ha-1 green compost with 100% NPK fertilization resulted in the longest ear length without husk (10.52 cm).                     

PENGARUH BERBAGAI DOSIS PUPUK KOMPOS ECENG GONDOK DAN PUPUK HIJAU Azolla microphylla TERHADAP PERTUMBUHAN DAN PRODUKSI TANAMAN PAKCOY (Brassica rapa L.)

The aim of the study was to know the influence of the interaction of water hyacinth compost doses and Azolla microphylla green fertilizer doses on the growth and production of pakcoy. The research was conducted in the greenhouse and plant ecology and production laboratory of the Faculty of Animal Science and Agriculture, Diponegoro University, Semarang, Central Java. The study was conducted in January to March 2020. The experimental design of this research was Completely Randomize Design (CRD) 5 x 3 factorial pattern design with 3 replications. The first factor consists of 5 levels, namely without fertilizer, inorganic fertilizer (NPK), 50% recommendation of water hyacinth compost doses, 100% recommendation of water hyacinth compost doses, and 150% recommendation of water hyacinth compost doses. The second factor consists of 3 levels, namely without fertilizer, 50% recommendation of Azolla microphylla green fertilizer doses, and 100% recommendation of Azolla microphylla green fertilizer doses. The observed parameters were plant height, number of leaves, crown wet weight, and the production of the crown’s dry matter. Analyzing the data use variance analysis and Duncan’s multiple range test of 5% level. The results showed that there was an interaction between the treatment doses of water hyacinth compost and Azolla microphylla green fertilizer on plant height, number of leaves, crown wet weight, and the production of the crown’s dry matter. The treatment of 100% recommendation of water hyacinth compost doses (138 kg N/ha) and 100% recommendation of Azolla microphylla green fertilizer doses (138 kg N/ha) gave the best results than other treatments. The treatment of 100% recommendation of water hyacinth compost doses (138 kg N/ha) without the addition of Azolla microphylla green fertilizer as the same as the contribution of inorganic fertilizer that had done for once during cultivation to increasing the crown wet weight

Nutrient Dynamics in Stormwater Runoff from Green Roofs with Varying Substrate

One major concern with urban development is the increasing amount of stormwater runoff from large expanses of impervious surfaces. These impervious surfaces reduce the ability of stormwater to infiltrate into the soil and eventually groundwater, which leads to greater amounts of surface runoff. Green technology serves as a viable solution to many of the environmental problems presented by modern development. Fifteen mock, extensive green roofs were built in the fall of 2008 at the Watershed Research and Education Center in Fayetteville, Arkansas. The goals of this project were to (1) measure the amount of stormwater runoff from varying treatments and control roofs, (2) measure the stormwater runoff quality from varying treatments, and (3) study the release of nutrients over time from the green roofs with added compost. Our results show that after an initial flush of nutrients from green roofs with added compost, many nutrient concentrations, such as total organic carbon (TOC), total nitrogen (TN), nitrate-N (NO3-N), and other physiochemical properties have been reduced. However, even after two years, P concentrations in runoff water still exceed 1 mg/L from green roofs using compost in the growing matrix. Analysis of the remaining nutrients in the compost shows that TP loads from green roofs with added compost could be elevated for a number of years. The results from this study provide a benchmark for developing green roofs in Northwest Arkansas or other similar climactic regions

Yields of relay cropped greens grown in green roof production systems

As interest in urban food production increases, urban farmers are looking for solutions to the challenge of space availability. One solution is to move production to building rooftops, a space that is often underutilized. The use of green roof technology is one method of achieving food production on rooftops; however, there are some additional challenges associated with this practice as a result of the fast-draining, low-nutrient media used. This is particularly challenging for vegetable crops, which typically require more nutrients than the ornamental plants traditionally grown in green roof media. Some rooftop farmers are adding additional organic matter in the form of compost to their beds as an alternative to chemical fertilizers. Currently, there is little research on how rooftop production systems affect crops. Green roof platforms were established at the Harold R. Benson Research and Demonstration Farm in Frankfort, Kentucky, to examine crop yield in green roof systems supplemented with compost. Treatments were a topsoil no compost control, a green roof media no compost control and 3 green roof media treatments: the addition of 0.33, 0.66, or 1 kg m-2 of compost. Organic fertilizers were used to supply additional nutrients to vegetable plants. The crops selected were lettuce, arugula, mizuna, mustard, Swiss chard, kale, and spinach. These were relay cropped in succession during two growing seasons (2018 and 2019). At each harvest, the amount of time harvesting required (in seconds), total yield, and marketable yield (determined by visual examination) were measured for each platform. Yield results were analyzed in R. Analysis of variance was performed on all variables for each crop; compost treatment and year were fixed effects. Significant differences between treatment means were analyzed using Tukey HSD (alpha of 0.05). Results for kale show differences between 2018 and 2019 for harvest time and total yield in the topsoil control, but no differences for marketable yield. These differences are likely due to weather conditions. Kale harvest time, total yield in 2019 but not 2018, and marketable yield were highest in the topsoil control. Harvest time of the topsoil control was not significantly higher than the 1 kg m-2 of compost in green roof media. The marketable yield of the topsoil control was not significantly higher than 0.66 or 1 kg m-2 compost treatments in green roof media. Results for additional crops will also be presented