摘要:

The distribution of leaf area and light intensity within wheat crops differing in row direction, row spacing and rate of sowing is described. Regardless of the manner of planting, 75% of the total leaf area was found within a band 31/2 in. wide, centred on the centre of the row. Light penetration within crops spaced at 14 in. was greater than within those spaced at 7 in. Light penetration within rows running N.–S. was more uniform and higher, particularly around noon, than within rows running E.‐W. Within N.‐S. rows the position midway between rows received the highest amount of light, but light decreased on either side until it was least beneath the rows. Within E.‐W. rows at 14 in. spacing, maximum light was recorded at 101/2 in. on the southern side of a row, decreasing progressively as the row was app

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00544.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Methods of testing grass varieties are discussed and the efifects of differences in management and of nitrogen fertilizer on quality are shown. In a grazing‐management system with 9 cuts per season, cocksfoot was higher than perennial ryegrass in protein and fibre and lower in soluble‐carbohydrate content andin vitrodry‐matter digestibility throughout the season. All species showed the lowest value for digestibility in August.Curves for digestibility in primary growth were plotted for 4 varieties of ryegrass for leaf and stem fractions. The tetraploid variety Reveille was slightly more digestible than S24 in leaf and stem throughout the period, while at ear emergence S23 was lower in digestibility in both fractions than S24.There were significant differenees in composition and digestibility between experimental centres, but relative differences between varieties were consistent. The level of N fertilizer did not materially alter the comparison between varieties in quality

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00545.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Populations of white‐ and red‐clover were examined after they had been grown for several years in grass/clover swards. The method of sowing, nitrogen application, management and season affected the ratio of very similar clover cultivars differing specifically in the leaf mark when sown in the same mixture. The companion grass also infiuenced the proportion of legume cultivars in the sward. In addition, the mean date of emergence of a single cultivar of broad‐red clover was affected by manag

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00546.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

A survey of heather regeneration following muirburn was undertaken over a range of sites and community types covering a wide area. The sites were all spring burned and a small grazing exclosure was erected on each after burning. Botanical analyses, height measurements and observations on grazing effects were made annually thereafter in late summer or early autumn.Several factors were found to be of importance in influencing heather regeneration, and the data collected are discussed from the standpoint of: the actual firing process, plant characteristics, biotic factors, site characteristics, and climatic factors.All factors may operate at any one site and may interact one with another. At many sites one factor may be of over–riding importance for a particular year of burning, but the same factor may not be of similar importance in subsequent year

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00547.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The use of lime and phosphates in reclaiming heather moorland was investigated in two experiments.Large initial dressings of hme resulted in a rapid rise in pH. An initial dressing of 9 tons CaCO3/ac resulted in a more rapid rise to pH 6 than did 6 tons/ac and the soil was maintained above pH 6 for a longer period. Three annual dressings of 3 tons/ac gave a slower rise in pH and a longer period above pH 6. Split treatments, half before and half after the first ploughing, gave no long–term advantage where a programme of pioneer cropping was being followed.Basic slag and North African phosphate were as effective as superphosphate for root crops at low pH values. Basic slag was as effective as superphosphate for grassland establishment and gave a greater rise in soil phosphate. North African phosphate was virtually worthless as a source of phosphate for establishing grasses and clovers, and gave a negligible rise in soil phosphate.Given adequate supphes of lime and phosphate, frequent small apphcations of N over the first 2 or 3 years are vital to the success of a reclamation programme under the conditions describe

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00548.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00549.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The results from 10 years of grassland research at the Peatland Experimental Station, Glenamoy, are summarized.Grass and legume species were introduced by surface seeding, without cultivation or by direct seeding after rotavation, depending on the specific situation. The rate of establishment was dependent on pretreatment and the management of grazing animals before and after sowing.The most suitable species wereTrifolium repens, Lolium perenne, Festuca arumlinacea, Festuca rubraandHolcus lanatus.A level of fertility suited to the introduced species must be reached initially and subsequently maintained. The requirements (per/ac) for Ca, P, K, N, Cu and Co were: 2240 lb (1016 kg) ground limestone, 36 lb (16 kg) P, 112 lb (51 kg) K, 20 lb (9 kg) N, 20 lb (9 kg) CuSO4and 2 lb (0–91 kg) CoSO4at sowing, with 27 lb (12–25 kg) P and 56 lb (254 kg) K annually.Dry–matter yields of 6000 lb/ac (6720 kg/ha) were obtained from grass–clover swards without fertilizer N, and approximately twice this quantity where 400 lb N/ac (448 kg/ha) had been applied annually. A liveweight gain of 526 lb/ac (589–12 kg/ha) and a starch equivalent output of 2946 lb (3299–5 kg) were obtained with sheep. The relationship between these results and those on peat soils abroad ar

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00550.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

There was a marked increase in basal cover of veld grasses after the first 2 to 3 years of cutting, and this effect continued over a period of 9 years. Short grasses, such asCynodon dactylonandHeteropogon contortus, increased at the expense of tall tussock grasses, such asHyparrhenia dissoluta.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00551.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Aqueous ammonia was injected to a depth of 10 cm into small grass plots in late winter at rates equivalent to 200 and 400 kg N per ha. The effect on yield of DM, seasonal distribution of yield and uptake of N in the herbage was compared with that of single or split applications of ammonium nitrate. Two levels of supplementary irrigation were given in summer. The method of injection minimised damage to the sward and loss of ammonia by volatilization.Aqueous ammonia and ammonium nitrate (single application) gave similar yields of dry matter, uptake of N and distribution of yield over the season. Ammonia was no more effective than ammonium nitrate under dry conditions. A single application in February of 200 kg N/ha as ammonium nitrate gave a greater total annual yield than the same quantity of N as ammonia or as a split dressing of the solid fertilizer. At 400 kg N/ha, split application gave the highest yields. The uptakes of N in the harvested grass was similar, in each irrigation treatment and at each level of N, for the three methods of applying N, The apparent recovery was low.Aqueous ammonia, efficiently injected, was a satisfactory form of N for grass at the first cut, but it did not provide a continuing supply of N for crops harvested later in that season.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00552.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Two experiments were established to compare the effect on the yield of continuously cut herbage of varying amounts of potassium fertilizer applied either in one large dose to the seedbed, or as 3 equal dressings applied to the seedbed and in the summer of the 2 following years. Responses in dry–matter yield were recorded up to the higher rates of potassium fertilizer applied. Establishment and yield in the first 12 months were improved by seedbed applications of up to 4 cwt/ac of muriate of potash (60% K2O). Although total yields over the whole period were similar, whether the potassium was applied to the seedbed only or in annual dressings, yields from “all–in–seedbed” dressings declined towards the end of the period. Soil analysis indicated that annual dressings left behind higher resi

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1968.tb00553.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY