摘要:

Infiltration into a transitional red-brown earth was analysed for the following ameliorative treatments: no treatment (C), surface gypsum at 8 t/ha (G), 8 t/ha of gypsum concentrated into slots 0.4 m deep and 0.66 m apart (SGI) or 1.0 m apart (SG2). Analysis consisted of fitting the infiltration data to the following equations:

ISSN:0114-0671    

DOI:10.1080/01140671.1989.10428029

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Changes in water content of four soil types from alluvium were monitored under spring-sown barley during 1978/79, spring-sown peas during 1979/80 and under pasture during September 1981 - August 1984. The soil types varied in texture and depth to sandy gravels and are representative of a large area of the Canterbury and North Otago Plains. Patterns of soil water depletion over time are depicted graphically for representative soils in each season. All crops extracted similar amounts of water from the upper 30 cm, but spring-sown crops extracted less water below 30 cm. In stone-free soils, pea and barley crops obtained more than 80% of their total soil water from above 60 cm depth, and pasture obtained less than 60% of total soil water from the same depth. Pasture grown in moderately deep and shallow soils extracted 70–80% of total soil water from above 60 cm. Spring-sown crops extracted water to 90–100 cm depth in stone-free horizons, but pasture extracted water to at least 120 cm in soils underlain by sandy gravels, and to 180 cm in deep stone-free soils. High amounts of soil water extracted by pasture from subsoil horizons were considered to be related to perching of water in sandy layers.

ISSN:0114-0671    

DOI:10.1080/01140671.1989.10428030

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Changes in water content of four soils from alluvium were monitored with a neutron probe during wetting up phases in two seasons. The soil types varied in texture and depth to sandy gravels and are representative of a large area of the Canterbury and North Otago Plains. Soil wetting from rainfall did not occur as a wetting front progressively restoring deeper layers to field capacity. Rather, initial rainfalls only partially restored the deficit of the upper 40–60 cm of soil material. Subsequent rainfalls progressively recharged these horizons, and, at the same time, water penetrated more deeply into the soil, partially wetting successively deeper horizons. In some cases, water penetrated to 120 cm before the uppermost horizons were fully recharged. A wet front formed by heavy rain when the soil was dry showed the marked spatial variability of wetting possible under heavy rainfall in these soils.

ISSN:0114-0671    

DOI:10.1080/01140671.1989.10428031

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

An empirical test to detect potato tubers susceptible to after-cooking darkening was developed from a histological method for revealing chlorogenic acid (CA). Since CA is the predominant compound responsible for after-cooking darkening, the test provides a simple field technique for use by potato breeders and food processors. No cooking is required, but suitable precautions must be taken with the reagents. The test kit uses two dry reagents: (1) a mixture of two parts urea with one part tartaric acid (wt/wt); and (2) sodium nitrite. Three 0.5 g scoops of the urea-tartaric acid mix are dissolved in 60 ml of tap water. Two scoops of sodium nitrite are added, then the solution is poured over potato slices. After 5 min, the slices are transferred to 2% sodium hydroxide for 2 min to develop a red colour where CA is present. Potatoes with unacceptable after-cooking darkening show CA deeper than 3–4 mm from the surface, either as surface staining 10 mm deep, or as pink coloration throughout the tuber. High CA levels just under the skin would be removed during peeling, so the total amount of CA is not as important as its localisation.

ISSN:0114-0671    

DOI:10.1080/01140671.1989.10428032

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Several techniques have been tried in emasculating flowers of which the simplest has been the finger nails on first three fingers.Prunusflowers have frequently been emasculated by this method (Moore & Janick 1983) but for pear and apple, more precise techniques generally have been used possibly owing to their more slender styles; such techniques are using notched scissors and notched blades. This paper describes an alternative tool that could be more efficient in emasculating Asian pear (nashi) flowers.

ISSN:0114-0671    

DOI:10.1080/01140671.1989.10428033

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0114-0671    

DOI:10.1080/01140671.1989.10428034

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor