Affluent “peri-urban” populations in some areas have created new markets for small specialized growers. Although intensive growing systems using drip irrigation and fertigation with new varieties can increase yields, there is also a desire to use systems that are viewed as more sustainable. One way to reduce the environmental impact of intensive systems is to use organic mulches that do not require disposal and can improve soil conditions. `Chandler' strawberry (Fragaria ×ananassa Duch.) transplants were set in raised beds on 28 Oct. 1997. All plots received pre-plant P at 73 kg/ha. Treatments were: hay mulch (HY); a commercial, pelleted, recycled paper mulch (PA); polyethylene mulch (PL); or a woven weed-blocking (WB) fabric, with or without dairy manure compost (22% moisture) at 22 t/ha tilled in before bedding. A total of 184 kg/ha N was applied through the irrigation system in weekly applications during the growing season. The first bloom set was killed by cold on 9 Mar. 1998. Yields from the two synthetic mulch systems (PL = 5502 and WB = 4996 kg/ha) were significantly higher than those from the organic mulches (HY = 2824 and PA = 1735 kg/ha). Mean fruit weight was also higher with synthetic (PL = 10.6 and WB = 10.4g) than organic (HY = 9.5 and PA = 9.0 g) mulches. Factors such as increased weed growth in organic mulches and warmer temperatures in synthetic mulches contributed to increased yields from synthetically mulched plots.
The goals of sustainable agriculture include decreased reliance on synthetic nutrients and pesticides and improved environmental quality for the long-term benefit of the land, livelihood of growers, and their communities. Cropping systems that maximize these goals use alternative fertility and pest control options to produce crops with minimal soil erosion and nutrient leaching. Cropping system elements that can help achieve these goals include: reduced tillage, cover crops, and organic soil amendments. Cover crops are grown before the cash crop and used to replenish the soil with nitrogen and organic matter. Cover crops often also influence pest populations and can be selected based on site-specific growing conditions. Cover crops can be mulched on the soil surface to prevent erosion and weed emergence or can be tilled directly into the soil to incorporate nitrogen and organic matter. Green waste mulch is an increasingly used soil amendment. Many municipalities are encouraging farmers to use green waste mulch in farming systems as an alternative to green waste disposal in landfills. Reduced tillage was once restricted to large-seeded field crops but recent technical advances have made it a feasible option for vegetables and other horticultural crops. Alternative farming practices; however, are still only used by a small minority of growers. Increases in price for organic produce and changes in laws governing farming operations may increase adoption of alternatives to conventional agriculture.
The use of spent mushroom compost (SMC) as a media amendment for containerized greenhouse and nursery crop production is a promising alternative to disposal of this by-product of mushroom production. Fresh SMC is the compost that is removed from the mushroom house and used without further weathering. The objectives of this study include first, identification of key factors involved its successful use and second demonstration of the effective use of SMC by nurserymen. The plant material used includes both bedding plants and woody perennial species. Results demonstrate that the key factor in the use of SMC for plant production is high soluble salts. Leaching can reduce the high soluble salts. In addition, special consideration should be given to the reduction in potted media volume over time due to composting that continues after the material is removed from mushroom production. SMC as the sole growing media was not as effective as when SMC was amended with a commercial nursery growing mix. Several species were grown in 0%, 25%, 50%, 75%, and 100% mixtures of SMC and a commercial nursery mix. All species grew well in 50% SMC/50% nursery mix.
Increasing costs associated with the disposal of industrial and urban wastes necessitate the development of alternatives which are economical and environmentally safe. With >3000 ha in Quebec, sod production represents an interesting alternative for the use of new amendments, such as composted de-inked paper sludges and municipal waste compost. The objective of this trial was to evaluate the potential benefits of these amendments (nutrient retention in the root zone and chemical and physical soil benefits) and question potential environmental hazards. Chemical dynamics of N, P, K, micronutrients and heavy metals were examined over four soil layers (0 to 15, 15 to 30, 30 to 60, an >60 cm) on sandy and clay soil. Preliminary results for 1993 and 1994 indicate that nutrient concentrations in water extract are high following the establishment of sites. When sod is absent, high concentrations of lead (500 mg·kg–1 in urban compost) show only a slight trend to accumulate. Nevertheless, this new approach toward using industrial and urban composts seems to be adequate and economically attractive.
Paper recycling generates large quantities of de-inking sludge, which is disposed of mainly by landfilling. More ecological disposal alternatives include land application and use as a container nursery medium. In this study, raw de-inking sludge was evaluated as a medium component supplemented with applications of four N fertilization regimes for the growth of three grass species (Festuca ovina duriuscula, Agropyron elongatum, Alopecurus pratensis), and four regimes of P fertilization for the growth of three Rhizobium-inoculated legumes (Medicago lupulina, Galega orientalis, Melillotus officinalis). Fertilizer was applied on the basis of sludge rate to maintain a uniform C: N ratio across sludge treatments. In one experiment, sand was mixed with 0, 10%, 20%, and 30% sludge by volume and 20% perlite, while in a second experiment, mineral soil was mixed with 0, 27%, 53%, and 80 % sludge and 20% perlite. Results indicate that shoot dry weight of all species increased with the amount of sludge in the mixture in tests with sand. In the soil mixture experiment, grasses showed the best response to treatments of 53% sludge mixture at the two highest N treatments. In general, shoot dry weight was more directly related to the total amount of N applied than to the C: N ratio of the substrate. The nutritional status (foliar N and P) also was investigated for one grass and one legume species.
Coal combustion by-products (CCB) are produced nationwide, generating 108 Mg of waste annually. Though varied, the majority of CCB are crystalline alumino-silicate minerals. Both disposal costs of CCB and interest in alternative horticultural/agricultural production systems have increased recently. Field studies assessed the benefit of CCB and organic waste/product mixtures as supplemental soil/growth media for production of hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy] sod. Growth media were applied at depths of 2 to 4 cm (200 to 400 m3·ha-1) and vegetatively established by sprigging. Cultural practices typical of commercial methods were employed over 99- or 114-day growth periods. Sod was monitored during these propagation cycles, then harvested, evaluated, and installed offsite in a typical lawn-establishment method. Results showed mixtures of CCB and biosolids as growth media increased yield of biomass, with both media and tissue having greater nutrient content than the control media. Volumetric water content of CCB-containing media significantly exceeded that of control media and soil included with a purchased bermudagrass sod. Once installed, sod grown on CCB-media did not differ in rooting strength from control or purchased sod. When applied as described, physicochemical characteristics of CCB-media are favorable and pose little environmental risk to soil or water resources.
Landfiling and incineration constitute the most commonly used methods of biosolid disposal. To minimize the environmental risk, their chemical and biological characteristics have been the subject of several investigations.
The present research was undertaken to evaluate the agronomic value of municipal solid wastes (MSW) and composted de-inked sludge (CDS) in a field experiment for sod production. Four variables in a split factorial design, were investigated at two sod farms: compost (MSW and CDS), soil (sandy loam and clay loam), application method (surface applied 6cm and incorporated 20cm), and the application rate (50-100 and 150t/ha). Controls consisted of unfertilized and unamended but fertilized plots. Both experimental sites were seeded with kentucky bluegrass.
Preliminary data indicate that the two biosolids promoted the sod growth at the rates applied. However, a better plot cover was observed if composts were rototilled at a depth of 6cm as compared to the conventional treated plots. Measurements of root and foliar weights revealed that the turf growth was enhanced with increasing rates, which is probably caused by additional soil macronutrients showed by the analysis. Seed germination and seedling emergence were not delayed as indicated by the observed increase in the water retention capacity of the soil especially at higher compost rates.
Measuring intact fruit with a colorimeter could be a quick way to estimate anthocyanin concentration and reduce waste disposal. Five fresh fruit from each of 134 plots were measured with a Minolta tristimulus colorimeter in 1994. Samples were frozen and anthocyanins extracted with acidified ethanol and measured with a spectrophotometer. The hue angle and anthocyanin concentration had r 2 = 0.51. L*, a*, b* and C* were significantly correlated with anthocyanin concentration with r 2 = 0.31, 0.32, 0.42, and 0.34, respectively. In 1995, five fruit from each of 20 plots were measured as before. In 1995, the hue angle and anthocyanin concentration had r 2 = 35. A regression equation with hue angle, b* and a* estimated anthocyanin concentration with R 2 = 0.62. In 1995, the same 20 samples were also measured with a colorimeter immediately after thawing. The hue angle and anthocyanin concentration had r 2 = 0.55. A regression equation with hue angle, b* and L* estimated anthocyanin concentration with R 2 = 0.76. It may be possible to estimate anthocyanin concentration by measuring intact fruit with a colorimeter after freezing and thawing the samples.
Large amounts of poultry litter are produced in eastern Oklahoma. Nitrate leaching from stockpiled litter can contaminate water supplies. Poultry producers need additional land for disposal of litter. Poultry litter can be a good fertilizer because it usually contains 2% to 3% N, P2O5, and K2O. The ratio of N: P: K is about 1:1:1. Soils in the area often need fertilizer with about a 1:1:2 ratio for cucumber production. This study was established to determine if poultry litter alone could be used to supply all of the nutrients needed for cucumber production, and if excess nutrients would be detrimental to crop growth. Treatments consisted of two rates of raw poultry litter, two rates of composted litter, and synthetic fertilizer applied in either a single or a split application. Treatments ranged from 112, 112, and 224 kg·ha–1. The greatest yield came from the highest rate of poultry litter. Composted litter did not yield more than raw litter. Splitting the application of synthetic fertilizer did not improve yields over that of a single application of the same material.
Animal waste disposal from large operations is an increasing problem, and its value as a fertilizer needs to be determined. Strip tests often are unreplicated creating problems in analysis. In an unreplicated Georgia farm test involving a three manure (0, 1, 2 loads/acre) × 3 N (0, 70, 90 lb/acre) factorial on corn yield from the control plot was not included, making n = 8, and precluding the usual ANOVA and means comparisons. Partial budget analysis is compared to regression analysis and economic evaluation at varying input costs and corn prices. Best estimates were obtained by finding the N equivalent of manure [(56.4 lb N)/load] and regressing yield on sum of N (Nf + Nm), which estimated Y = –14.0 + 1.1724N – 0.00324NN, RR = .982, F = 136.38, P > F =.000, sye = 3.0 bushel/acre, from which Nmax = 181, Ymax = 92.1 bushel/acre. Nopt varied from 139 to 172 bushel/acre with cost N varying from $0.14/lb (manure cost) to $0.40/lb, and corn prices from $1.50 to $2.50/bushel. Manure thus valued at 16.92 per load when costing $8.00, assuming 56.4 lbs/load N. Major point was estimation N equivalent of manure from yield effects and then regression yield on N. Equation easily converted to one in M.