Yield soil condition

As noted, the alkaloid yield from the Beocin plants was low, which the authors suggested might be caused by the poor soil in which the plants were growing (Popovic et ah, 1992). One could ask whether the soil conditions to which they refer might be influential in the overall alkaloid biosynthetic processes in this species. It would be of interest to see experimental studies aimed at determining the effect of soil components on these processes. In the present case, it may be a lack of, or reduction in the activity of, the oxidase(s) necessary for the dimerization process (required to form the bibenzyldihydroisoquinolines) to occur. It is also possible that the lack of dimeric alkaloids may simply reflect a concentration effect caused by the edaphic conditions. These questions should be accessible to experiment. 

As a soil develops, OM decomposes to produce humus, which is black. Additionally, release of iron from minerals by weathering yields various reds and yellows. Both mechanisms yield soil coloring agents. Under oxidizing conditions, where soil is not saturated with water, the iron will be oxidized and thus in the ferric state [Fe(III)]. When the iron and OM are deposited on the surfaces of sand, silt, clay, and peds, they develop a coat that gives them a surface color. However, soil color is not only a surface characteristic but extends through the soil matrix. Under oxidizing conditions, soil has a reddish color. The chroma of this color depends to some extent on the amount of and the particular iron oxide present. 

CASRN 957-51-7 molecular formula CieHiyNO FW 239.30 Soil. Degradation of diphenamid in soils yields desmethyldiphenamid via monodemethylation and a bidemethylated product of diphenamid (Somasundaram and Coats, 1991). The persistence of diphenamid under warm-moist soil conditions ranged from 3 to 6 months (Ashton and Monaco, 1991). 

Schonbeck, M., Stephen, H., DeGregorio, R., Mangan, F., Guillard, K., Sideman, E., Herbst, J. and Jaye, R. 1993. Cover cropping systems for brassicas in the Northeastern United States 1. Cover crop and vegetable yields, nutrients and soil conditions. Journal of Sustainable Agriculture 3 105-132. 

As a result of modern agricultural technology and farmer trial and error, great progress has been made toward the development of systems that provide long-term sustainability with reasonable use of agricultural chemicals. Farmers are concerned about weed control, weather, soil conditions, crop yield, and environmental stewardship. Alternatives to herbicides often come with costs or tradeoffs, such as increased soil erosion, lowered operational efficiency, more land needed, or reduced profits. 

White Riesling moderate vigor with good yields (5-8 tons/acre). Matures late season. Most cold-hardy of V. vinifera varieties and adaptable to a wide range of climatic and soil conditions. Buds are extremely fruitful (often four clusters per shoot), which can lead to overcropping. It is the most widely planted vinifera in the state. Sensitive to Botrytis cinerea. 

Sprague, H.B., Farris, N.F., and Colby, W.G., The effect of soil conditions and treatment on yields of tubers and sugar from the American artichoke (Helianthus tuberosus), J. Am. Soc. Agron., 27, 392-399,1935. 

Carbon and nutrient element allocation and redistribution, J. Plant Nutr., 22, 1315-1334, 1999. Sprague, H.B., Farris, N.F., and Colby, W.G., The effect of soil conditions and treatment on yields of tubers and sugar from the American artichoke (Helianthus tuberosus), J. Am. Soc. Ag ron., 27, 392-399, 1935. Stauffer, M.D., The potential of Jerusalem artichoke in Manitoba, in Annual Conference Manitoba Agronomics, Manitoba, Canada, 1975, pp. 62-64. 

STRAWBERRIES AND RASPBERRIES. These are the most demanding in terms of soil requirements. They should be grown only on medium-heavy to light, free-draining soils. Areas with compaction or waterlogging are unsuitable. Reduced yields and root disease problems are unavoidable on unfavourable soils. Planting by the hill system is to be recommended if soil conditions are not entirely optimal. 

One dream of the biosynthetic chemist is to develop a system of stabilized enzymes on solid supports, permitting a continuous flow process from precursors to products. With no variability due to climate or soil conditions, yields would be totally controllable and reproducible, and product clean-up would be greatly simplified, or ideally, unnecessary. With the isolation, characterization, cloning, and expression of more enzymes in biosynthetic pathways, the reality of the dream moves inexorably closer. Already the use of enzyme systems for directing stereospedfic reactions in organic synthesis has risen dramatically, with a corresponding increase in efficiency and enantio selectivity. 

Agricultural technicians also work for the government, research groups, and companies that produce fertilizers and other farm chemicals. They know how to modify soil conditions, increase crop yields, help crops resist disease and insects, and store produce. Some agricultural technicians help keep farm animals healthy and productive. 

Equation 3.41 requires that the standard states of the products and reactants be known, that the components can be defined quantitively and in a thermodynamic sense. In soils and much of nature these definitions are rarely possible. The states of ions or molecules in soil systems, and in probably all colloidal systems, are ill-defined thermodynamically. In rigorous thermodynamic terms even ions are undefined. Soil reactions, because of the nonequilibrium in soils and the lack of defined standard states, yield reaction coefficients, rather than reaction constants, and their values vary with soil conditions. 

Gas diffusion is slower in wet and flooded soils, where soil pores are plugged by water. Gas diffusion in water is about 1/10 000th the rate of gas diffusion in air, or essentially nil in flooded soils where all soil pores are water-filled. The consumption of 1 mole of O2 during respiration yields approximately 1 mole CO2. In flooded soils, therefore, CO2 can almost completely replace O2 and reach a partial pressure of 0.2, equal to the value of O2 in atmospheric ah. Since the gas volume in a flooded soil is minute, it is perhaps more instructive to say that the CO2 concentration in the soil solution is equivalent to Pqo2 = 0.2. At such concentrations, dissolved CO2 has considerable influence on soil pH (Eq. 7.18). When soil solutions are extracted from soils, dissolved CO2 is slowly lost to the atmosphere. This causes large pH increases in extracts from alkaline and flooded soils, and the possible precipitation of CaCC>3 and of transition and heavy metal hydroxyoxides. The loss requires several hours so immediate measurements yield pH values more representative of actual soil conditions. 

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