Compost Rates Research Articles

Compost Addition Enhanced Hyphal Growth and Sporulation of Arbuscular Mycorrhizal Fungi without Affecting Their Community Composition in the Soil.

Arbuscular mycorrhizal (AM) fungi form symbiotic associations with most crop plant species in agricultural ecosystems, and are conspicuously influenced by various agricultural practices. To understand the impact of compost addition on AM fungi, we examined effect of four compost rates (0, 11.25, 22.5, and 45 Mg/ha) on the abundance and community composition of AM fungi in seedling, flowering, and mature stage of soybean in a 1-year compost addition experiment system in Northeast China. Soybean [Glycine max (L.) Merrill] was used as test plant. Moderate (22.5 Mg/ha) and high (45 Mg/ha) levels of compost addition significantly increased AM root colonization and extraradical hyphal (ERH) density compared with control, whereas low (11.5 Mg/ha) level of compost addition did not cause significant increase in AM root colonization and ERH density. AM fungal spore density was significantly enhanced by all the compost rates compared with control. The temporal variations analysis revealed that, AM root colonization in seedling stage was significantly lower than in flowering and mature stage. Although AM fungal operational taxonomic unit richness and community composition was unaffected by compost addition, some abundant AM fungal species showed significantly different response to compost addition. In mature stage, Rhizophagus fasciculatum showed increasing trend along with compost addition gradient, whereas the opposite was observed with Paraglomus sp. In addition, AM fungal community composition exhibited significant temporal variation during growing season. Further analysis indicated that the temporal variation in AM fungal community only occurred in control treatment, but not in low, moderate, and high level of compost addition treatments. Our findings highlighted the significant effects of compost addition on AM growth and sporulation, and emphasized that growth stage is a stronger determinant than 1-year compost addition in shaping AM fungal community in black soil of Northeast China.

Application of Biochar and Compost for Enhancement of Rice (Oryza Sativa L.) Grain Yield in Calcareous Sandy Soil

ABSTRACTThe application of compost to calcareous soils by farmers is a well-established practice and has been shown to improve yields. However, incorporation of biochar and mixture of biochar and compost into calcareous soils is a relatively novel concept for improving soil quality and yield since calcareous soils comprise a large scale of soils worldwide. The objective of this study was to determine the effects of the co-application of biochar and compost on the soil properties, nutrient status and grain yield of rice in calcareous sandy soil. The experiment was conducted in a factorial arrangement based on randomized complete block design with three replications. The compost application rates were 1% and 3% (w/w; compost/soil) and the applied rates of biochars (rice straw biochar, RSB; sugarcane bagasse biochar, SBB) were 0.3% and 0.9% (w/w; biochar/soil). The results showed that soil pH decreased with increasing application rates of either compost or biochars. However, soil EC was enhanced through increasing the application rates of compost and biochars. The co-application of biochar and compost improved soil total N and available P concentrations. The soil available K increased with increasing the rate of incorporated biochars and compost. An increase of soil available K was more predominate with the application of RSB than SBB. The RSB, also, added a considerable amount of silicon (Si) to the soil. The co-incorporation of biochars and compost enhanced soil available concentrations of Fe, Zn, Cu, and Mn as well. The RSB was more effective than the SBB in grain yield enhancement almost certainly due to a higher Si content in RSB. Furthermore, the concurrent application of biochars and compost increased grain yield more than applying them individually. A higher application rate of biochar and compost induced a higher grain yield. The co-application of highest rates of RSB (0.9%) and compost (3%) induced the highest grain yield (26.1 g/pot) among the treatments. The increase in yield compare to the control were 321% and 260% for 0.9% RSB + 3% compost and 0.9% SBB + 3% compost, respectively. The increase in the grain yield was due to an improvement in the soil chemical properties and nutrients enhancement. Finally, the co-application of the highest rate of RSB (0.9%) and compost (3%) is recommended to obtain the appropriate rate of rice grain yield in calcareous sandy soil.

ORGANIC AMENDMENTS AND THEIR EFFECT ON STATUS OF SOME NUTRIENTS IN SOIL AND PLANT

The aim of this investigation was to study the application impact of biochar “RSB” and compost “RSC” derived from rice straw on sandy soil and its leachates properties. These properties were pH, EC and soluble nutrients (N, P, K, Zn and Cu). Also, the effect of RSB and RSC applications on the growth of sunflower plants and its content of N, P, K, Zn and Cu were studied in the pot experiment.In addition to the properties of the sandy samples and its content of available N, P, K, Zn and Cu were studied. To achieve this study, two experiments were conducted namely, leaching and pots at the laboratory and green house of Soil Sci. Dept., Fac. of Agric., Menoufia Univ., Shebin Elkom, Egypt. The results indicated that, the applications of Biochar resulted in an increase of leachate pH, EC and soluble K and a decrease of soluble NH4+ , NO3-, P, Zn and Cu. This decrease was non-significant with NO3-. Increasing rates of individual applications of compost associated with an increase of EC, soluble HN4+, NO3-, P, K and Zn and a decrease of pH and soluble Cu in leachate. After leaching, application rates of biochar were associated with an increse in soil pH, EC, CEC and available NH4+, P and k and a decrease in available Zn and Cu. While, the application rates of compost resulted in an increse in EC, CEC and available NH4+, NO3-, P , k, Zn and Cu and a decrease in soil pH. Uptake of N, P and k (mg/plant) by sunflower plants was increased with biochar rates increasing up to 0.05% biocharcompared with the control and decreased with increasing of biochar rates. Zn and Cu uptake was decreased with increasing biochar rates. The effect of compost application at 0.75% increased uptake of N, P, k, Zn and Cu compared with the control.

THE GROWTH RATE OF CELERY (Apium graveolens L.) AT VARIOUS COMPOSITIONS OF ORGANIC AND SYNTHETIC FERTILIZER

This study was aimed at assessing the growth and production of celery plants grown with various compositions of N,P and K fertilizer and compost. The study was done at the Trial Farm of Faculty of Agriculture, Djuanda University, Bogor fiom September to November 2015. A completely randomized design with two factors was used. The factors consisted of compost rate and N,P and K fertilizer rate. Compost was given in four levels, namely no compost (0% R), 26.3% gcompost/plant (50% R), 52.5 g compost/plant (100% R), and 78.7 g compost/plant (150% R). N, P and K fertilizer was given in five levels, namely no fertilizer (0% R), 4 g Urea, 0.3 g SP-36, 0.2 g KCl (25% R), 0.9 g Urea, 0.6 g SP-36, 0.4 g KCI (50% R), 1.3 g Urea, 0.8 g SP-36, 0.6 g KCl (75% R), and 1.7 g Urea, 1.1 g SP-36, 0.8 g KCl (100% R). All fertilizers were administered gradually at the time of planting and 2 weeks after planting. Three replicates were allocated into each treatment making up 60 experimental units. Results showed that celery plants given synthetic fertilizer at 100% R had higher plant height, number of leaves, number of seedlings, harvest fresh weight (g), saleable fresh weight (g), root biomass (g), and root dry weight (g) than those treated with no fertilizer (0% R). Plants treated with 150% compost had higher plant height, number of leaves, harvest fresh weight (g), saleable fresh weight (g), root length (cm), and root dry weight (g) than those treated with no fertilizer (0% R). Thus the best celery growth and production in this study was obtained on plant 150% R compost and 100% R synthetic fertilizer nourished.Key words: celery, compost, N, P, K fertilizer, harvest flesh weight

Effects of incubation period and Christmas Island rock phosphate with different rate of rice straw compost on phosphorus availability in acid soil

Phosphorus (P) availability is limited in tropical acid soil due to fixation of soluble inorganic P by aluminium (Al) and iron (Fe). Liming is one of the common ways to overcome this problem. However, this practice is not economical. The aim of this study was to evaluate the effects of laboratory incubation period and different rates of rice straw compost on the soil P availability. During the incubation study, Christmas Island rock phosphate (CIRP) fertilizer was amended with different rates of rice straw compost (5, 10, 15, and 20 t ha−1). Treatments were incubated in the laboratory for 30, 60, and 90 days. Application of rice straw compost with CIRP significantly increased soil available P at 30, 60, and 90 days of incubation, respectively. This implies rice straw compost plays an important role on soil P availability by decreasing the P adsorption due to the competing adsorption sites by organic anion and dissolving the mineral associated P by low-molecular-weight organic acids. Besides, rice straw compost also increased the soil pH, and, at the same time, reduced exchangeable acidity, exchangeable Al and Fe. As the soil pH increased, the compost effectively fixed the Al and Fe in the soil instead of P, thus increasing the P availability in the soil. However, there was no significant increase/loss of available P when the incubation time increases under treatments with rice straw compost. This implies the effectiveness of rice straw compost in minimizing the loss of P due to P fixation in soil and slow microbially mediated mineralization of soil organic P to inorganic P as incubation time increases. The findings suggest that the application of rice straw compost altered soil chemical properties in a way that enhanced the availability of P in the Rengam acidic soil.

Supstrati za organsku proizvodnju rasada paradajza

One of the main tasks for every certified organic vegetable producer is to grow healthy and well-developed transplants. The aim of this study was to examine different substrates designed for the production of organic tomato transplants. On the basis of preliminary experiments, seven substrates consisting of different parts of natural peat, vermicompost, shrub and tree leaves compost and zeolites were compared with standard commercial substrates using tomato (Solanum lycopersicum L.) transplants grown in pots. The data concerning plant height, number of leaves, fresh plant mass, appearance of flower buds were collected. The differences in the examined traits were not significant for the majority of substrates. The zeolite-based substrate with high peat and vermicompost content achieved the best results and its production for the market should be considered. Three zeolite-based substrates with high rates of vermicompost and compost should be used as a model for tomato transplants substrate preparation.

Enzyme activity in soil after different procedures for managing rice straw

Severe problems are caused by site burning of rice straw in Valencia, the third largest Spanish city. Removal, incorporation or composting are being tested as alternatives to burning, and the changes they produce in selected soil biological properties have been studied in two field trials. One compares removal, burning and incorporation the straw, and a second evaluates the application of straw-derived compost for rice production. No statistically-significant effects on the measured indicators of biological activity were found in either experiment, indicating that management-induced changes are small. Unexpectedly, burning did not affect negatively enzyme activities or microbial biomass contents since there were no differences between treatments, or usual levels were recovered in a few months. The changes induced by straw removal or incorporation were also not statistically significant. When straw-derived compost applications were assayed, dehydrogenase activity was slightly variable and apparently unaffected by N and compost rates or compost/mineral N combinations, but phosphomonosterase activity seems to increase parallel to compost to mineral N ratio.

Effects of co-composted maize, sewage sludge, and biochar mixtures on hydrological and physical qualities of sandy soil

The agronomic utilization of compost has some benefits to soil. Compost increase soil nutrients, and soil organic matter content; thus, it has a positive effect on biological, physical, and chemical properties of the soil. During the composting process, different feedstocks such as plant wastes, sewage sludge, and biochar are used. Biochar has great potential to improve the quality of compost. This paper reports the effects of different compost rates and feedstock types of biochar on water retention characteristics of sandy soil in a standard natural turfgrass root zone.Using soil with the texture of loamy sand, a pot experiment was established. The following mixtures of feedstocks were used in this study: compost of maize straw (MS), compost with sewage sludge (MS+SS), and compost of mixture of maize straw, sewage sludge, and biochar (MS+SS+BC). Mixtures of compost additives and soil were prepared at 0.5% (R05), 1% (R1), 2% (R2), and 4% (R4).Compared to untreated soil, the physical properties of the sandy soil were significantly improved with the application of compost. The basic physical parameters of the soil, such as bulk density and total porosity, depended mainly on the rate of the biochar additive. The differential porosity of the soil was affected by both compost rate and feedstock type. For compost with sewage sludge, the highest content of large pores with diameters above 500μm was observed, and this was achieved with biochar addition. Addition of the compost also significantly increased the volume of pores with diameters below 50μm compared to the untreated control soil. The water retention properties of the soil were improved with the compost application and were dependent on the rate of compost and the type of feedstock. The lowest value of available water content (AWC) was obtained for soil with maize straw compost. The addition of sewage sludge or biochar during the composting process resulted in an increase in AWC in the soil. The best combination of compost rates and feedstock types is maize compost with both sewage sludge and biochar at a rate of 4%.

Effectiveness of Compost and Potassium Silicate under Low Rate of Mineral Fertilizers on Production, Quality, Marketability and NPK Contents of Banana Plants

Banana (Musa spp) is considered as one of the most important fruit crops in Egypt, where it occupy an area of 27.5 thousand ha. Field experiments on banana cv. Grand Nain for two consecutive seasons (2016 and 2017) were conducted in Horticulture Research Station located in El-Kanter Elkharia, Kaluobia Governorate. The main objective of this study was to investigate the possibility of reducing the mineral fertilizers applied to the banana crop by using compost and potassium silicate treatments. Three rates of compost (15, 20 and 25 kg per mate) were applied with 50% of the recommended rate of mineral fertilizers along with or without potassium silicate at a rate of 60 ml per mate. These treatments were compared with recommended rates of mineral fertilizers mixed with and without potassium silicate. Obtained results showed that application of compost led to enhance all studied parameters and recorded highly significant differences particularly under the treatments combined with potassium silicate and 50% of the recommended rate of mineral fertilizers. The highest level of compost with potassium silicate treatment recorded the uppermost values of growth, yield and quality of banana fruits. Moreover, the same treatment recorded significant increments in total sugar and T.S.S% in fruits as compared with the recommended dose of mineral fertilizers.

Effects of Sludge Compost on EC value of Saline Soil and Plant Height of Medicago

In this study, the effects of sludge composting on the EC value of saline soil and the response to Medicago plant height were studied by planting Medicago with pots for 45 days in different proportions as sludge composting with saline soil. The results showed that the EC value of saline soil did not change obviously with the increase of fertilization ratio,which indicated that the EC value of saline soil was close to that of the original soil. The EC decreased by 31.45% at fertilization ratio of 40%. The height of Medicago reached the highest at 40% fertilization ratio, and that was close to 60% fertilization ratio, and the difference was significant with other treatments. By comprehensive analyse and compare,the optimum application rate of sludge compost was 40% under this test condition.

EFFECT OF COMPOST FERTILIZATION LEVELS ON GROWTH, YIELD AND CHEMICAL COMPOSITION OF SANDY SOIL GROWN AMMI VISNAGA PLANTS

The present investigation was conducted at the nursery of Fac. of Agric., Minia Univ. during the two successive seasons of 2014/2015 and 2015/2016 to explore the most suitable level of compost for Ammi visnaga plants grown in sandy soil. All studied vegetative growth characters (plant height, branch number and herb dry weight/plant); yield parameters (number of umbels/plant and seed yield per plant and per fed); and chemical constituents (photosynthetic pigments and herb percent and content of N, P and K) were gradually increased parallel to the increase in compost level added to the soil. However, no clear difference was obtained, for all prementioned traits, between the medium compost level (12.5 ton/fed) and the high one (17.5 ton/ fed). In general, seed yield per fed, due to medium or high compost rate was increased by about 30%.

Biochar-compost mixture as amendment for improvement of polybag-growing media and oil palm seedlings at main nursery stage

PurposeProduction of oil palm seedling in the nursery mainly utilises top soil as polybag medium. These soils, especially in tropical regions, are acidic and have low organic matter content. The aim of this study was to investigate the effects of oil palm empty fruit bunch (EFB) biochar and compost incorporation as amendment in polybag medium for oil palm seedlings growth at the nursery stage.MethodsA polybag experiment was conducted with four biochar rates (0, 0.5, 1.0 and 1.5% w/w C addition), two compost rates (0 and 30% v/v), and two fertiliser application rates (75 and 100% of recommended rate). The effects of biochar, compost, and biochar-compost combination on oil palm seedling growth was evaluated and the effectiveness of EFB biochar in retaining soil nutrients was determined indirectly by measuring amount of nutrient leached through the polybag medium.ResultsBiochar, compost, and biochar-compost amendment improved polybag media’s chemical properties (pH, total C and N, C:N ratio, CEC, Mg, and Ca). There were no significant effects of the amendments on shoot biomass. However, root growth and shoot:root ratio significantly improved with 1.5% w/w C addition and 30% (v/v) compost with 75% recommended fertiliser rates applied. Furthermore, nutrient leaching measurement indicates that, EFB biochar significantly reduced ammonium-N leaching up to 21–46%.ConclusionsOverall, this study demonstrates the potential of biochar and compost co-application to improve the chemical properties of polybag medium and root development of oil palm seedlings.

Growing Substrates, Fertilization, and Irrigation for Creeping Bentgrass Establishment on Sand‐Based Putting Greens

Growing substrates, fertilizer inputs, and irrigation are important factors for grow‐in of sand‐based putting greens. The research reported here was triggered by grow‐in problems encountered in 2015 after replacing garden compost with Sphagnum peat in the rootzone on a sand‐based green at the NIBIO Turfgrass Research Center, Norway. A pot trial was conducted with the same type of sand amended with: (i) 20% (v/v) garden compost, (ii) 10% (v/v) Sphagnum peat, (iii) equal volumes of (i) and (ii), (iv) 10% (v/v) Sphagnum peat plus lime (200 g CaCO3 m−2), and (v) 10% (v/v) Sphagnum peat plus phosphoric acid, 5 g P m−2. The amendments were tested with or without preplant application of chicken manure (5 g N and 2.5 g P m−2) and at the two irrigation rates: 3 and 12 mm d−1. The pots were seeded with creeping bentgrass (Agrostis stolonifera L.), and turfgrass coverage and clipping yields were recorded for 5 wk after seeding. Turfgrass coverage developed significantly faster and clipping yields were significantly higher after amendment with compost than after amendment with peat or peat plus lime. Incorporation of chicken manure did not enhance grow‐in on substrates containing full or half rates of compost but improved grow‐in on peat, especially when combined with phosphoric acid. Excessive irrigation had no impact on turfgrass coverage but reduced clipping yields on substrates containing compost, compost plus peat, or peat plus phosphoric acid. We conclude that the grow‐in problems encountered in 2015 were most likely due to inadequate quality of the Sphagnum peat.

Soil chemical properties and growth response of Moringa oleifera to different sources and rates of organic and NPK fertilizers

PurposeThe need for increasing production of Moringa oleifera in Nigeria can be achieved through adequate fertilization. This study investigated the effects of sources and rates of NPK (15:15:15) and compost on soil properties and productivity of Moringa at National Horticultural Research Institute, Ibadan, Nigeria.MethodsNPK was applied at 30, 60, and 90 kg N/ ha, cow dung (CD), poultry manure (PM) and organomineral (OM) were applied at 10, 20 and 30 tons/ha. The experimental design was a randomized complete block design with three replicates. Organic fertilizers were incorporated into the soil 2 weeks before sowing; NPK was split applied at 2 and 5 weeks after sowing. Seeds were sown at 75 cm × 75 cm spacing. Data were taken on plant height (cm), stem girth (cm), number of leaves, leaf biomass, stems weight and post-planting soil properties.ResultsGrowth values for NPK and compost treatments were higher than the control. PM applied at 30 tons ha−1 resulted in highest growth values: plant height (65.91 cm), stem girth (1.51 cm) and number of leaves (14.20). PM applied at 30 tons ha−1 gave higher stem weight (2249.9 g) and leaf biomass (3610.5 g). Post-planting soil analysis indicated that nitrogen, phosphorus, calcium, sodium, manganese, iron and zinc contents were higher in plots with organic and inorganic fertilizers except for potassium and magnesium.ConclusionPM proved more superior to CD manure and others because it produced better growth attributes such as shoot height, stem girth and number of leaves and leaf biomass than its counterparts produced.

Yield and sward composition responses of a native grassland to compost application

A major part of the animal products are based on the grasslands, due to the fact that the grassland ecosystems can be found all over the globe. In places where economical and successful crop production cannot be realized, the grassland based animal husbandry can be an efficient way of food production. In addition these ecosystems have an important role in carbon sequestration, and with their rich flora – and the fauna connected to it – in conservation of biodiversity. The protection of nature, and the sustainable agriculture is getting more and more attention in the European Union, but looking at the consumers’ needs, the production of healthy food cannot be neglected either. Because of these facts, the effects of two specific composts - which are officially authorized in organic farming, in Agri-environment Schemes and Natura 2000 programs – on grass yields and sward compositions were investigated in a field trial. The investigation took place in Hungary, on a natural grassland based on solonetz soil. The first type of compost was a natural one (N) without any additional material and the other one was enriched in phosphorus (E). Both was produced by the research institute, made of sheep manure. Three rates of compost (10 t ha-1, 20 t ha-1,30 t ha-1) were tested on 3 m×10 m experimental plots. Every treatments had four replications and both type of compost had four-four control plots too, this way 32 experimental plots were included in the investigations. The yield of the pasture was harvested two-times (in May and in September) and before cutting the plots measurements on botanical compositions were made. Samples for laboratory analysis were also taken. Dry matter yield and crude protein content was measured in laboratory and with the received data the yield per unit area was calculated. Based on the research results we can say that the application of compost in any dose inflicts higher dry material and crude protein yield. The changes were partly due to some positive changes in sward composition, because of the better nutrient conditions. The research results indicate, that use of organic compost can be an efficient way to increase grass yields in a sustainable way.

Lettuce and cabbage growth and nutrient uptake response to invasiveAcaciawaste composts

Peat moss and pine bark have been traditionally used in the production of horticultural substrates. However, there is an increasing demand for alternative materials to produce horticultural substrates. In order to determine the potential use of composts made of shredded biomass from the control activities with respect to the invasive Acacia species (Acacia longifolia and Acacia melanoxylon) as an alternative to pine bark compost for the production of horticultural substrates, we assessed the effect of increasing rates of composts of Acacia in a commercial substrate, on growth of lettuce (Lactuca sativa L.) and savoy cabbage (Brassica oleracea sabauda L.). The replacement of pine bark compost by Acacia compost did neither affect lettuce nor cabbage growth negatively, thus suggesting that Acacia compost can be successfully used as an alternative constituent for horticultural substrates. Increased growth and nutrient uptake was found for lettuce and cabbage in treatments with Acacia compost compared with bark compost, which may be explained by the lower C/N ratio and the increased availability of N in the Acacia compost, compared with pine bark compost. Therefore, Acacia composts can be recommended for substrate formulation, although it may be needed to decrease its electrical conductivity and pH value by mixing it with other constituents such as peat. Crop and container characteristics must be considered for recommendations about the optimum proportion of Acacia compost in final substrate composition.

Optimization of food waste compost with the use of biochar

This paper aims to examine the influence of biochar produced from lawn waste in accelerating the degradation and mineralization rates of food waste compost. Biochar produced at two different temperatures (350 and 450 °C) was applied at the rates 10 and 15% (w/w) of the total waste to an in-vessel compost bioreactor for evaluating its effects on food waste compost. The quality of compost was assessed against stabilization indices such as moisture contents (MC), electrical conductivity (EC), organic matters (OM) degradation, change in total carbon (TC) and mineral nitrogen contents such as ammonium (NH4+) and nitrate (NO3−). The use of biochar significantly improved the composting process and physiochemical properties of the final compost. Results showed that in comparison to control trial, biochar amended compost mixtures rapidly achieved the thermophilic temperature, increased the OM degradation by 14.4–15.3%, concentration of NH4+ by 37.8–45.6% and NO3− by 50–62%. The most prominent effects in term of achieving rapid thermophilic temperature and a higher concentration of NH4+ and NO3− were observed at 15% (w/w) biochar. According to compost quality standard of United States (US), California, Germany, and Austria, the compost stability as a result of biochar addition was achieved in 50–60 days. Nonetheless, the biochar produced at 450 °C had similar effects as to biochar produced at 350 °C for most of the compost parameters. Therefore, it is recommended to produce biochar at 350 °C to reduce the energy requirements for resource recovery of biomass and should be added at a concentration of 15% (w/w) to the compost bioreactor for achieving a stable compost.

Pot-grown Swiss chard and kale responses to variable rate of manure compost in mycorrhizal fungi inoculated medium

Pot-grown Swiss chard and kale responses to variable rate of manure compost in mycorrhizal fungi inoculated medium

Effects of composts obtained from olive oil production wastes on organic tomato seedling production

The aim of this experiment was to evaluate by-products of olive oil production in compost production and to test them in different rates as tomato ('Melis') seedling growing medium. Therefore, three different types of olive oil production wastes (two-phase and three phase olive mill wastes and olive oil waste water sludge) were composted with separated dairy manure, poultry manure, and straw using aerated static pile composting methods to obtain three different types of composts separately. Additionally, each compost was enriched with cotton seed meal, potassium salt, and rock phosphate. In the experiments, different rates (25, 50, 75 and 100%) of six different composts were added to peat which is locally available. Seeds were sown on July 21, 2015. Each treatment had 4 replicates and each replicate included 64 plants in a tray. Seedlings were fertilized by liquid composted farmyard manure and seedlings were ready for transplanting after a month. Some physical and chemical properties of each growing medium, germination rate of seeds and seedling vigor were determined. Germination period extended with the increase of compost rates in peat. Compost materials obtained from the mixture of olive oil production wastes were found to be appropriate in composting without a need of enrichment and their performances were close each other due to the changes in terms of their effects on tested characteristics. However, results were promising in order to be able to evaluate the olive oil wastes in seedling production and a rate of 25% could be proposed.

English

Two sets of pot experiments were conducted to investigate the effect of different compost types (market compost, home compost and vermicompost) and their rates on growth of pot grown tomato. During the first experiment, two compost types (market and home composts) each applied at four rates (0, 200, 400 and 800 g/pot) were evaluated while during the second experiment all the three compost types including vermicompost each applied at five rates (0, 200, 400, 600 and 800 g/pot) were evaluated. The chemical compositions of the composts were analyzed using appropriate laboratory procedures. Results revealed that market compost had the highest available P, exchangeable K and total S content whereas vermicompost had the highest organic matter and total N content followed by market compost. Growth parameters increased with increasing rates of home compost and vermicompost, but decreased with increasing rate of market compost. Shoot nutrient content varied much between compost types than compost rates. Shoot nitrogen and potassium concentration was higher with the application of market compost; phosphorus concentration was higher with the application of vermicompost while sulphur concentration was the highest with the application of home compost. Growth reduction at the highest market compost application could be ascribed to higher pH and total soluble salt content, especially chloride and potassium. Key words: Compost, salt stress, tomato, toxicity, vermicompost.