Search Results

You are looking at 11 - 20 of 62 items for

  • Author or Editor: Allen V. Barker x
Clear All Modify Search
Author:

Major compostable materials in municipal solid wastes (MSW) are sewage sludge, paper, garbage, and autumn leaves. Five composts made from these wastes separately or in mixtures and one compost made from agricultural wastes (chicken manure and cranberry pomace) were evaluated for production of grass sods. Perennial ryegrass (Lolium perenne L. 'Pennfine') was seeded in 3.5-cm-deep layers of compost in plastic trays and grown in a greenhouse. Seed germination was inhibited in immature sludge-based and mixed MSW composts relative to germination in the other composts. High ammonium levels in the immature sludge-based and mixed MSW composts appeared to limit germination, as these composts had ammonium-N levels ranging from 1,000 to 2,000 mg/kg. Ammonium-N in the agricultural compost was 200 mg/kg, whereas that in the leaf-based composts was 10 mg/kg. In general, germination in all media was sufficient to establish a stand. Thereafter, growth of sods in the sewage-based, mixed MSW, and agricultural composts benefitted from the rich supply of N and exceeded that in the leaf-based composts. Mixing of composts with soil gave no advantage other than slightly increased seed germination but diluted total N supply and increased weediness of the sods.

Free access
Author:

Abstract

Until the development of modern chemical fertilizers began in about 1840, natural and organic materials supplied virtually all the plant nutrients to the soil. The use of chemical fertilizers increased gradually until about 1940. Since then the total consumption of chemical fertilizers in the United States has increased nearly fivefold to about 40,000,000 tons annually (28). The development and use of modern chemical fertilizers has decreased the relative importance of organic fertilizers. Today, organic materials account for less than 1% of the N fertilizers sold in this country (27). Phosphate rock materials account for about 20% of the present P fertilizer consumption in the United States, and over 85% of these materials are consumed in Illinois and Missouri (4). Natural potassic fertilizers, such as seaweed, greensand, and granite dust, apparently account for an insignificant fraction of the K fertilizer materials sold in this country, since muriate of potash alone accounts for nearly 90% of the commercial K fertilizers consumed here (4).

Open Access
Free access
Free access
Free access
Free access
Free access