Regional Economic Diversity and Diversification

ABSTRACT Regional scientists have long attempted to develop meaningful definitions and measures of economic diversity and diversification, and to establish functional relationships between diversity, diversification, and economic performance. The multiplicity of definitions and measures explains, in part, the confusion about these relationships. A framework that sorts out the overlaps, contradictions, and gaps of the various definitions and measures IS needed. Such a framework would explicitly address the question, “What is the relationship between a region's changing economic structure and performance?” In this paper it is suggested that an input-output model that incorporates elements of portfolio theory be used as the integrating framework for analysis.     

Silage intake and milk production in cows given barley supplements of reduced ruminal degradability

Three change-over experiments were conducted to determine the effect on ad libitum silage intake and milk production in dairy cows of treatment of barley supplements with an acid-formaldehyde reagent designed to reduce the rate of starch and protein digestion in the rumen. In Experiment 1 there were six dietary treatments consisting of silage with supplements of 4·0,6·5 and 9·0 kg d^-1 of barley given untreated or treated with formaldehyde reagent (8·1 t^-1). In Experiment 2 there were four dietary treatments consisting of silage with supplements of barley (7·0 kg d^-1) or barley and fishmeal (6·0 kg d^-1 plus 1·0 kg d^-1), with the barley untreated or treated with formaldehyde reagent (15·1t^-1). In Experiment 3 there were four dietary treatments consisting of silage given alone or with supplements of barley (9·0 kg d^-1). Treated barley (15·1 t^-1, 9·0 kg d^-1) and barley plus sodium bicarbonate (9·0 kg d^-1 plus 25·0 g d^-1). Treatment of the barley supplement with formaldehyde reagent had no effect on silage intake or milk production in Experiment 1 where the rate of application of the reagent was low and the basal silage-barley diet was limiting in rumendegradable nitrogen. However, in Experiments 2 and 3 treated barley supplements were associated with improvements in silage intake and milk production. As compared with corresponding control diets containing untreated barley, increases in silage intake ranged from 0 to 0·16 of the control value, whilst associated increases in the yields of milk, milk fat, milk protein and lactose were 0·077–0·089, 0·016–0·026, 0·092–0·118 and 0·080–0·092 of the control value. These responses are discussed in relation to the increases in silage intake and milk production observed with fishmeal supplementation of the diet in Experiment 2 and inclusion of sodium bicarbonate in Experiment 3.     

Growth and water relations of simulated swards of Lolium perenne L. selection lines with contrasting leaf osmotic potentials

Two selection lines of Lolium perenne , which had different leaf lamina osmotic potential (Ψ_s) when droughted in controlled environments, were grown as vegetative simulated swards in containers of soil 1·0 × 1·3 × 0·9 m deep in the glasshouse. Water was withheld during July, August and September.
Under irrigation the low-ψ_s line had leaf lamina and leaf base ψ^s 0·06 MPa lower than the high-ψ_s line. Under drought, the two lines did not differ significantly in lamina ψ_s but leaf base ψ_s was 0·16 MPa lower in the low line than in the high line. Upon rewatering, most of the osmotic adjustment in the leaf bases was lost within 2 d, but that in the laminae was more stable.
Herbage growth under irrigation was similar in the two lines until September, when it was greater in the highψ_s line. Drought reduced herbage growth, and also regrowth rates following rewatering, but the two lines did not differ in their sensitivity to drought.
Selection for low ψ^s also increased leaf extension rates, and reduced tillering and leaf water conductance of irrigated plants.
The results are discussed in relation to selecting for improved drought resistance on the basis of physiological characters.     

安徽省望江县油菜田土壤有效硫状况及硫肥效应

选择长江流域油菜主产区望江县研究安徽省土壤有效S状况和油菜施用S肥的效应.结果表明,望江县土壤有效S平均含量15.31 mg/kg,缺S状况较为严重,缺S土壤所占比例高达61.29%,潜在性缺S土壤所占比例为35.48%.主要土壤类型中灰潮土缺S状况最为严重,有效S不足的土壤所占比例高达80%.在有效S极为缺乏的灰潮土上,油菜施用S肥具有极为显著的增产效果,与施尿素的对照相比,盆钵栽培增产1O.89%～26.21%,田间试验产量提高9.42%～16.43%,平均增产15.80%和13.29%.