Twenty four French Alpine goats (39 ± 2·0 kg) were individually housed in a completely randomized design and fed a basal diet containing 146 g crude protein and 356 g neutral detergent fibre (NDF)/kg in the absence (control – CTRL) or presence (CELL) of 2 ml of cellulase/kg dry matter intake (DMI) for 70 days, which included a 10-day adaptation period. The feed was offered three times daily at 07·00, 13·00 and 19·00 h, but the single daily dose of cellulase was only fed at 07·00 h. Goats were hand-milked daily; milk production recorded and samples taken for compositional analysis. During the last 5 days of the experimental period, goats from each group were individually housed in stainless steel metabolic cages to enable separate and total collection of faeces and urine for nutrient digestibility and ruminal fermentation determinations. Goats fed CELL had greater DMI and greater digestibility of dry matter (DM), organic matter and NDF than CTRL goats. CELL goats had greater ruminal pH, concentration of acetic acid and concentration of propionic acid than CTRL goats. However, the concentration of ruminal butyric was lower in CELL goats compared with CTRL goats. CELL goats had greater milk yield, energy corrected milk, milk energy content, milk energy output and milk density than CTRL goats and the milk content for total solids, fat, protein and lactose were also greater for CELL goats than for the CTRL goats. The milk of CELL goats had greater palmitoleic acid, cis-10-heptadecanoic acid content and mono-saturated acids than the milk of CTRL goats and lower linoleic acid, linolenic acid contents and saturated fatty acids than the milk of CTRL goats. These results suggest that addition of 2 ml cellulase/kg DM of feed in the diet of lactating French Alpine goats elevated their milk production and improved its composition probably due to improved feed utilization.

Fifty-one Scottish Blackface ewes were divided into three groups and individually fed throughout the latter half of pregnancy: (I) in excess of their nutrient requirements, (II) to produce a uniformly moderate degree of undernourishment throughout the final 6 weeks of pregnancy, and (III) to produce a uniformly severe degree of undernourishment during the same period.

Marked differences were evident in the amounts of feed required to maintain the prescribed nutritional states, and within the undernourished groups, between ewes with single and twin foetuses. In both groups of undernourished ewes the amount of feed required to maintain the prescribed level of undernourishment during late pregnancy was strongly related (P < 0·001) to birth-weight. The additional nutrient requirement of the ewe in late pregnancy was estimated to be 100 g D.o.m./kg foetus/day.

Root and shoot growth and nutrient uptake have been monitored for several winter wheat crops which gave a mean grain yield of 9·5 t/ha (85% D.M.) when grown on three soil types in 1980 and 1981. Averaged over all crops, maximum growth rates were 170 kg/ha/day for shoots and 14 kg/ha/day for roots; maximum nutrient uptake rates for N, P, K, Ca and Mg were 2·75, 0·47, 341, 0·60 and 0·18 kg/ha/day respectively. Maximum uptake of K and Ca occurred at anthesis with values of 239 and 38 kg/ha respectively, whilst for the other nutrients maximum uptake was at final harvest with values of 200, 39 and 14 kg/ha for N, P and Mg respectively. The grain contained 141 kg N, 27 kg P, 41 kg K, 3·2 kg Ca and 7·1 kg Mg/ha.

The quantity of nutrients arriving at root surfaces by mass flow was calculated for one of the crops from measurements of soil solution concentration and potential evapotranspiration data. The potential supply of nutrients by mass flow, as a percentage of that actually taken up between 19 March and 29 June, was 25% for N, 4% for K, 800% for Ca and 32% for Mg.

1. The serum β-globulin phenotype of 141 bulls located at Cattle Breeding Centres in England and Wales was determined by starch-gel electrophoresis.

2. The distribution of the contemporary comparison values of these bulls with respect to β-globulin type was investigated. The great majority of the bulls were βAA, βAD, or βDD with very few βAE and βDE and no βEE types.

3. The contemporary comparison values for 130 bulls of the three types βAA, βAD and βDD each fell into a normal distribution. The mean and its standard error and the standard deviation of the mean and its standard error were calculated for each of the three curves. The mean contemporary comparison value for the βAA bulls was + 12·2 ± 5·4 gal., for the βAD bulls + 26·8 ± 5·4 gal., and for the βDD bulls + 38·2 ± 5·5 gal. The βAA and βDD means were significantly different (P < 0·01).

4. The pooled contemporary comparison values of the βAA, βAD and βDD bulls did not give a normal distribution curve, neither did the contemporary comparison values for a sample of 1028 bulls quoted by the Milk Marketing Board. However, when the contemporary comparison values of the βAA, βAD and βDD groups were superimposed around the same mean, the ensuing distribution was normal.

5. It is concluded that the β-globulin locus is concerned in the genetic control of milk yield. The estimated mean genetic value of βD over βA is approximately + 50 gal. This is about one-sixth of the total genetic variation in milk yield in the major milk breeds.

6. The distribution of butterfat percentages with respect to β-globulin phenotype in four Ayrshire and one Friesian herds was investigated. No difference between the mean first lactation butterfat percentage of the βAA, βAD, and βDD cows in each herd was found. There was an indication (not significant) that the mean butterfat percentage of the βAE and βDE cows in three of the four Ayrshire herds studied was higher than the mean of the other groups.

Thirty-four soils from the Rothamsted Experiments were exhaustively cropped with ryegrass in the glasshouse. The concentration and yield of potassium in ryegrass tops and the potassium intensity in the soil were measured every 4 weeks, after harvesting the grass.

The change in K-intensity of soils, rich in potassium, with exhaustion differed from that of ‘poor’ soils. This change was related to the rate of change of the cumulative K-yield. The rate of change of soil K-intensity demarcated periods of intense and limited exhaustion and partial recovery of the soil during cropping.

The cumulative K-yield of ryegrass was very significantly related to the K-intensity of the uncropped soil; the ‘16-week’ yield was slightly better related than the ‘60-week’ yield. For Park Grass soils, the relationship was improved by allowing for variations in soil pH.

The K-intensity of all soils, with or without manuring, decreased to nearly 10-3 (M)½ in (AR)0 units after 16 weeks cropping, although large differences in K-yield persisted until much later.

K-buffer capacity per unit clay content of the soil, measured by a laboratory method, was inversely related to the K-intensity of the uncropped soil. The K-buffer capacities of soils rich in potassium, measured in laboratory and glasshouse experiments, were significantly related, but were unrelated for ‘poor’ soils. The K-buffer capacity (laboratory method) of Rothamsted soils with different manurial treatments was only very approximately related to the cumulative K-yield.

Less K was taken up from all Rothamsted soils given nitrogen fertilizer in the field and their K intensities were also smaller than the corresponding soils without ‘N’. Field liming of acid soils decreased their K-intensity and increased their K-buffer capacity, presumably because more potassium was removed by the field crop.

A rapid method is suggested for measuring potassium intensities of soils.

1. The longissimus dorsi muscles of cattle have been analysed for moisture, intramuscular fat (and its iodine number), nitrogen (total, myofibrillar, sarcoplasmic, soluble non-protein and stroma), myoglobin, total soluble phosphorus and ash; ultimate pH and buffering power were also determined.

2. At birth, in the region of the 4th, 5th and 6th lumbar vertebrae, total, myofibrillar, sarcoplasmic and soluble non-protein nitrogens have attained 87, 76, 71 and 25% of their mean adult values, respectively; the concentration of stroma nitrogen diminishes by 50%, between birth and maturity.

3. The mean adult values (fat-free basis) for sarcoplasmic (0·9%) and myofibrillar (1·9%) protein nitrogen, for total nitrogen (3·6%) and for moisture (76·8%) are atained at approximately 5 months, 7–10 months and 18 months of age, respectively; moisture on a whole tissue basis decreases fairly regularly as intramuscular fat increases.

The changes in the buffer components and pH in the surface layer of a pig and a cattle slurry were studied in the laboratory of the Department of Soil Science, Lincoln University in 1994. The slurries were spread to a depth of 7 mm in Petri dishes open to the atmosphere. Slurry pH, total inorganic carbon (TIC = CO2 + HCO- + H2CO3), total ammoniacal nitrogen (TAN = NH3 + NH4+) and volatile fatty acids (VFA = C2-C5 acids) were determined at 8–10 intervals after 1–96 h of incubation at 10, 16 and 22 °C. A great increase in pH over the first 8 h was due to the release of CO2. If the initial TIC > TAN, pH then increased steadily but slowly from 8 to 96 h. When the initial TIC < TAN, the pH declined or did not change after 20 h incubation. The initial pH elevation rate increased with temperature and initial concentration of TIC. Calculation indicated that the NH3 partial pressure (PNH3) in equilibrium with the slurry increased and pH decreased at increasing temperature if gases could not exchange between the slurry and the atmosphere. From the open slurry system PNH3 increased with temperature during the first 1–20 h. At 16 and 22 °C the PNH3 declined to low values after 20 h, whereas at 10 °C the PNH3 remained appreciable after 20 h. This explains why high accumulated NH3 losses may occur when slurry is applied to the field at low temperatures.

Experiments made between 1967 and 1970 tested the effects of sowing oilseed rape on different dates in autumn and spring. Much greater oil yields were obtained from autumn sowings, due to higher seed yields and oil content, but the effect varied considerably between experiments, varieties and seasons. Autumn-sown crops flowered in late April or early May, and by the time pods were developing rapidly in June the leaves had senesced almost completely. Spring-sown varieties followed a similar pattern but about a month later, and did not reach the same peak in pod growth.

There was a major effect of sowing date, late-autumn sowings (after mid-September) giving lower yields than early-spring sowings. The best autumn sowings (early September) gave about 3 t/ha of seed, but late sowings less than half this; oil content also decreased with delay in sowing – from 45% to as low as 38%. Delayed sowing restricted growth, leaf area and pod production, and also had a slight effect on seed weight. Frost damage on flower buds appeared to be the cause of reduced yield from early sowing (August) in one experiment. In spring, the earliest sowing (late March) gave the best yields. Vigorous but late vegetative growth from the latest sowing (end of April) did not lead to high yields, possibly due to pest and disease effects.

The effects of ploughing or no-tillage of long-term grass and grass-clover swards on changes in organic C and N pools and on CO2 and denitrified gas emissions were investigated in a 3-year field experiment in 1996–99 near Penicuik, Scotland. The decrease in soil C content between 1996 and 1999 was 15·3 t/ha (95% confidence limits were 1·7–28·9 t/ha). Field estimates of CO2 losses from deep-ploughed, normal-ploughed and no-tillage plots were 3·1, 4·5 and 4·6 t/ha over the sampling periods (a total of 257 days) in 1996–98. The highest N2O fluxes were from the fertilized spring barley under no-tillage. Thus no-tillage did not reduce C emissions, caused higher N2O emissions, and required larger inputs of N fertilizer than ploughing. By contrast, deep ploughing led to smaller C and N2O emissions but had no effect on yields, suggesting that deep ploughing might be an appropriate means of conserving C and N when leys are ploughed in. Subsoil denitrification losses were estimated to be 10–16 kg N/ha per year by measurement of 15N emissions from incubated intact cores. A balance sheet of N inputs and outputs showed that net N mineralization over 3 years was lower from plots receiving N fertilizer than from plots receiving no fertilizer.

Understanding the role of pollinators in determining the outcrossing rate is very important for the development of synthetic varieties of faba bean. Isozyme markers have been used to study the multilocus outcrossing rate in five cultivars under field conditions and in two locations. The study was carried out at Córdoba (Spain) and at Rennes (France). These two locations were chosen because previously studies showed strong differences in cross-pollination. Multilocus outcrossing rates at both locations, Córdoba and Rennes, were 0·65 and 0·33 respectively. Local differences in pollinator abundance and foraging activity were 26 and 32 times higher, respectively, at Córdoba than at Rennes which could explain an outcrossing rate twice at Córdoba compared with Rennes. So, pollinators may play a prominent role in determining the differences in outcrossing between locations. However, at a local level, there is a highly significant positive correlation between foraging activity and outcrossing only at Rennes (where the number of pollinators is scarce) but not at Córdoba (where pollinators are abundant). We suggest that although pollinators have a major impact on the level of outcrossing, in circumstances where there are a lot of pollinators the differences in outcrossing between cultivars depends on other factors among which is the ability of the genotype itself to outcross. No type of floral display seems to be clearly important in the determination of the outcrossing level in such a case. The implication of our results for faba bean breeding strategies is discussed.

Rations for dairy cows are often formulated using predictions of voluntary feed intake calculated from regression equations. The accuracy of the predictions of dry-matter intake by seven equations is investigated. Comparisons are made when live weight is taken to be the observed weekly mean (MLW), the observed live weight after calving (CLW) or an estimated breed weight accompanied by a notional pattern of live-weight change (BLW). Data recorded on a British Friesian dairy herd at the Grassland Research Institute fed mostly silage ad libitum and various supplements are used. The mean square prediction error (MSPE) is calculated for each week and summarized over the whole experimental period.

The least MSPE's are 2·1, 2·8 and 2·4 (kg D.M.)2 for comparisons using MLW, CLW and BLW respectively. The Ministry of Agriculture, Fisheries and Food (1975) equation involving only live weight and milk yield performs well and would be useful when only the limited measurements of live weight and milk yield are available, but the more complex equations of Vadiveloo & Holmes (1979) and of Lewis (1981) give consistently the best predictions. The importance of using the original definitions of the variables when applying a predictive equation is illustrated. Even so, the large errors found in the predictions of intake points to the need for further research.

Dutch agriculture has undergone significant changes in the past century, similar to many countries in the European Union. Due to economies of scale and in order to remain economically profitable, it became necessary for farmers to increase farm size, efficiency and external inputs, while minimizing labour use per hectare. The latter has resulted in fewer people working in the agricultural sector. Consequently, Dutch society gradually lost its connection to agricultural production. This divergence resulted in a poor image for the agricultural sector, because of environmental pollution, homogenization of the landscape, outbreaks of contagious animal diseases and reduced animal welfare. Although the general attitude towards agriculture seems to have improved slightly in recent years, there is still a long way to go in regaining this trust.

In order to keep the Dutch countryside viable, farmers are considered indispensable. However, their methods of production should match the demands of society in terms of sustainability. This applies both to farming systems that are used in a monofunctional way (production only) and to multifunctional farming systems. For researchers involved in development of these farming systems, this requires new capabilities; contrary to the situation in the past, citizens and stakeholder groups now demand involvement in the design of farming systems. In the current paper, it is suggested that, besides traditional mainstream agriculture, other alternative farming systems should be developed and implemented. Hence, Dutch agricultural research should remain focused on the cutting edge of economy and society. Despite all efforts, not all of these newly developed systems will acquire a position within the agricultural spectrum. However, some of the successful ones may prove extremely valuable.

Three field experiments in Eastern England, in which 15N-labelled fertilizer had been applied to winter wheat, were used to measure the persistence of the labelled N remaining in soil and stubble at harvest and the availability of this N to up to four subsequent wheat crops. A portion of the labelled fertilizer N quickly became stabilized in the soil, with only small and ever-decreasing amounts recovered by subsequent crops. Combining all sites, all years and all applications of fertilizer, 6·6±1·92 (S.D.) % of the labelled fertilizer remaining in soil (0–70 cm) plus stubble in the year of application was taken up by the next wheat crop, i.e. by the first ‘residual year’ crop. A further 3·5±0·39% was taken up in the second residual year, 2·2±0·43% in the third and 2·2% in the fourth. Loss of residual labelled N was more rapid from a sandy soil than from two heavier-textured soils, particularly in the first residual year. After four residual crops on one of the heavier soils (at Rothamsted), 16% of the labelled N remaining in soil (0–70 cm) and stubble in the year of application had been taken up by the crops, c. 29% had been lost from the soil/crop system and 55% remained in the soil.

Energy balances have been determined, using the comparative slaughter procedure, over 3-week periods on groups of laying hens kept at ambient temperatures of 7·2, 15·6, 23·9, 29·4 and 35 °C.

Energy intake declined as the environment became warmer (kcal ME/kg¾/day = 203· 1·13°C); heat production, as measured by the difference between energy intake and energy retention, also declined with increasing ambient temperature (kcal/kg¾/day = 151 – 1·11°C). There was a linear relationship between heat production and ambient temperature with no thermoneutral zone or critical temperature.

The energy available for egg production remained almost constant at 50 kcal/kg¾/day equivalent to a rate of egg production of 82% at each ambient temperature.

1. During the course of the alkali fractionation and the preparation of the humic precipitates, the qualitative characters of the fractions were followed by employing a standard hydrolysis with dilute acid. Humic acid itself was shown to be unhydrolysed by this reagent, and, therefore, the extent of hydrolysis of a humic fraction can be used as a criterion of purity.

2. Studies on the fractionation of the humic precipitate with aqueous, anhydrous, and alcoholic bases, led to the following conclusions:

(a) The humic precipitate as normally prepared i s always a mixture of true humic acid with varying amounts of co-precipitated material of a non-humic nature.

(b) This non-humic material is not an integral part of the humic molecules, it is merely co-precipitated and adsorbed contaminants.

(c) The non-humic material is differentiated from the humic acids by the following properties: (i) it is hydrolysable with acid; (ii) it does not give the characteristic nitro-humic compound on nitration.

Crop yield and optimum nitrogen fertilization rates (Nopt) are often calculated ex post by specific functions of the nitrogen fertilization rate, but in doing this, uncertainties in terms of model choice, annual nitrogen response variations and parameter estimation are neglected. In the present study, Nopt, grain yields, net revenues and N balances were estimated for the three crops of an oilseed rape (OSR)–winter wheat–winter barley rotation. The effects of uncertainties were considered using three different statistical models, estimating an identical Nopt over the years and carrying out Monte-Carlo simulations where model parameters were varied according to their estimated standard errors. The statistical models used were the quadratic (Q) polynomial function, the linear response and plateau (LRP) function and the quadratic response and plateau (QRP) function.

The Q model tended to estimate the highest Nopt values for the three crops, followed by the QRP and the LRP model in an initial ex post analysis. The highest corresponding mean net revenues in the rotation were estimated by the LRP model, followed by the Q and QRP model; mean N balances increased in the order LRP, QRP and Q. In the comparison of the crops, OSR showed the highest N balances followed by wheat and barley. Considering the protein concentration in wheat, Nopt values estimated by the Q model were considerably higher than without the economic effects of grain quality.

In order to consider uncertainties in annual nitrogen response, an ex ante Nopt over the years was determined by maximizing the cumulated net revenues over all years in the rotation. Ex ante Nopt was higher as the mean of the ex post Nopt values for the QRP and LRP model. Average grain yields and net revenues were lower, N balances were higher. Running the Monte-Carlo simulations, ex post Nopt was obtained by 10 000 generated functions in each year and ex ante Nopt by 50 000 generated functions of years 1996, 1997, 1998, 1999 and 2002. This led to an increase in Nopt especially for the LRP model, while effects on the estimation of Nopt by the Q model were rather small. For the LRP model, corresponding mean net revenue decreased and mean N balance rose. In contrast, due to marginal changes in Nopt, the consideration of uncertainties in the estimations had only a small effect on net revenue and N balance in the Q model.

In general, all kinds of uncertainty tended to increase Nopt but this effect was much higher for the LRP model as compared to the Q model. This increase in Nopt was associated with decreasing net revenues and increasing N balances. Exceptionally in OSR using the Q model, however, the ex ante approaches considering uncertainty led to slightly lower Nopt values compared to the ex post value.

Nitrous oxide (N2O) emissions associated with urine nitrogen (N) deposition during grazing are a major component of greenhouse gas emissions from domestic livestock. The present study investigated the relationship between urine N loading rate and the efficacy of a nitrification inhibitor, dicyandiamide (DCD), on cumulative N2O emissions from a grassland soil in Ireland over 80 and 360-day periods in 2009/10 and 2010/11. A diminishing curvilinear relationship between urine N rate and cumulative N2O emissions was observed in both years. Despite this increase in cumulative N2O emissions, the emission factor (EF3) for N2O decreased with increasing urine N rate from, on average, 0·24 to 0·10% (urine applied at 300 and 1000 kg N/ha, respectively), during an 80-day measurement period. This was probably the result of a factor other than N, such as carbon (C), limiting the production of N2O. The efficacy of DCD varied with urine N loading rate, and inter-annual variability in efficacy was also observed. Dicyandiamide was effective at reducing N2O production for 50–80 days after urine application, which accounted for the major period of elevated daily flux. However, DCD was ineffective at reducing N2O production after this period, which was likely a result of its removal from the soil via degradation and leaching.

About sixty male lambs were fed ad libitum from 6 weeks of age on low- or highprotein diets based on barley or barley and fishmeal and containing respectively 120 and 200 g crude protein/kg dry matter. Some lambs were changed from one diet to the other when they reached 28 kg live weight. All were slaughtered as they attained a predetermined series of live weights ranging from 20 to 75 kg.

Throughout the experiment, rates of live-weight gain were substantially higher with the high-protein (HP) than with the low-protein (LP) diet, but were highest after a change from low to high protein (LHP). The feed consumption of the LHP lambs did not exceed that of the HP lambs, but the former showed a substantial superiority in feed conversion ratio at the same live weight.

At similar empty body weights, the LP lambs contained more fat and less water in the empty body than the HP lambs. Although the percentage differences decreased at higher weights, differences were still apparent at 70 kg live weight.

The LHP lambs showed dramatic and rapid changes in body composition, particularly in water and fat content. By 40 kg live weight, their composition approached that of the HP lambs.

The ratio of water to protein was consistently lower for the LP lambs. The ratio of protein to ash also differed between LP and HP lambs. It was initially highest for the HP lambs, at about 40 kg live weight it was the same, and at 70 kg live weight it was highest for the LP lambs.

The ash content of the LHP lambs remained virtually constant during the period of rapid growth and rapid deposition of water, protein and fat which took place immediately after the change of diet, and only showed compensatory increases after 35 kg live weight. This finding was supported by the pattern of changes in weight and specific gravity of the femur and tibia + fibula.

Use was made of separate relationships between live weight and body composition for the LP, HP and LHP lambs to estimate rates of accretion of crude protein, fat and water in the empty body. There was a particularly striking increase in the rate of accretion of water immediately following the change of diet. There was an increase in the water content of empty-body gain and a reduction in the ratio of gain in fat to gain in protein.

Derived estimates of the ratio of metabolizable energy intake above maintenance to the energy content of empty-body gain gave some suggestion of an improvement in efficiency of utilization of metabolizable energy for gain following the change from low to high protein. It is concluded however that the improvement in food conversion ratio following the change is attributable mostly to difference in the composition of gain.

Three groups of red deer hinds of 9–10 years of age were grazed upon an indigenous hill pasture (A), an improved species grass sward (predominantly perennial ryegrass) maintained at < 1500 kg D.M./ha (B), and one maintained at 2000 kg D.M./ha (C) from immediately after calving on 29 May until weaning on 22 September. Numbers of hinds in each treatment were 8, 6 and 9 respectively. Milk yields of hinds were estimated on swards A and C by the calf-suckling technique and hind and calf live-weight changes and hind grazing behaviour were recorded on all three swards during lactation.

Hinds on award C yielded on average 60% more milk over the lactation period than hinds on sward A, day 40 yields being 2·2 and 1·5 kg/day respectively. Calf growth rates (treatment A, 257 ± 9·5, B, 324 ± 12·1 and C, 369 ± 14·5 g/day) were higher on the improved species sward than on the hill sward and higher on the improved sward with the greater herbage mass. On treatments A and C calf growth rates were significantly (P < 0·05, r = 0·69) correlated with milk yield throughout lactation. At weaning, calves on sward C were 7·5 and 4·5 kg heavier than those on swards A and B respectively. Biting rates were lower (33 v. 56 bites/min) and grazing times higher (11.7 v. 6.0 h) on sward A than swards B and C. The poorer performance of hinds and their calves on sward A was considered to be due to a lower quality of diet ingested, and to behavioural limitations on intake occurring when hinds graze indigenous swards of relatively high species diversity. These results are discussed in relation to the grazing behaviour of cattle and sheep on similar swards.

The significance of the results to red deer farming in the U.K. is briefly discussed.

1. The use of a positive air pressure on closely packed soils decreases the time of recovery and increases the yield of solution obtained by water displacement.

2. Equipment and technique for the recovery of displaced solutions is described.

3. Data from three sandy loams and two silty clay loams are reported.

4. Successive displaced solutions of equal electrical conductivity were obtained from each soil. The concentration thus measured was in each case the same as that of the liquid obtained without the use of displacing water.

5. Concentrations of individual ions in successive portions of displaced solution are uniform in soils at optimum and this also appears to be true at half optimum.

6. There is an inverse proportion between total moisture content of soil and concentration of displaced solution as indicated by measurements of specific resistance.

7. When the solution displaced by water from a given mass of soil was used as displacing agent on another portion of the same soil, the newly displaced solution had the same concentration of electrolytes as the displacing solution. The opinion is expressed that this result indicates that the displaced solution has the same concentration as the solution with which it came in contact in the soil.

8. Typical differences in behaviour of the various solutes in displaced solutions are discussed.

9. The significance and limitations of water extractions of soils are discussed in the light of the results from displaced solutions.