In a stretch of arable lands like those of the Ganges Valley, although damage may be caused by occasional floods, which are sudden and of short duration, the more general, and by far the most serious loss is due to deficiency of moisture of the soil: thus the relation of the soil to soil moisture becomes of more than ordinary importance. Dr Voelcker, in his Report on Indian Agriculture, remarks: “In India the relation of soils to moisture acquires a greater significance than almost anywhere else.......” This relation is fundamental, for on it depends the methods for the conservation of soil moisture, for the economical application of irrigation water, and for the treatment of barren and salt lands—all problems of direct interest to agriculturists in the plains of Northern India. The methods for dealing with these problems must be largely—if not entirely—empirical until such time as the behaviour of the soil in its relation to moisture is investigated. The problem in all its various branches is enormous, and in a country in which the seasons follow each other with such rapidity, and vary the one from the other in so marked a manner, it frequently happens that a particular point, if not determined within a period of a few days, must await solution until the following year.

The extent of the reduction of maize (Zea mays L.) kernel moisture content through drying is closely related to field temperature (or accumulated temperature; AT) following maturation. In 2017 and 2018, we selected eight maize hybrids that are widely planted in Northeastern China to construct kernel drying prediction models for each hybrid based on kernel drying dynamics. In the traditional harvest scenario using the optimal sowing date (OSD), maize kernels underwent drying from 4th September to 5th October, with variation coefficients of 1.0–1.9. However, with a latest sowing date (LSD), drying occurred from 14th September to 31st October, with variation coefficients of 1.3–3.0. In the changed harvest scenario, the drying time of maize sown on the OSD condition was from 12th September to 9th November with variation coefficients of 1.3–3.0, while maize sown on the LSD had drying dates of 26th September to 28th October with variation coefficients of 1.5–3.6. In the future harvest scenario, the Fengken 139 (FK139) and Jingnongke 728 (JNK728) hybrids finished drying on 20th October and 8th November, respectively, when sown on the OSD and had variation coefficients of 2.7–2.8. Therefore, the maize kernel drying time was gradually delayed and was associated with an increased demand for AT ⩾ 0°C late in the growing season. Furthermore, we observed variation among different growing seasons likely due to differences in weather patterns, and that sowing dates impact variations in drying times to a greater extent than harvest scenarios.

1. The potassium, sodium, calcium, magnesium and phosphorus contents of the grass and clover fractions of a perennial rye-grass and white clover sward were determined at each of five cuts taken between May and October in 1962 and 1963.

An analysis of data from the complete dissection of one side from 285 animals from a breed comparison experiment was conducted to determine whether there were important biases in the prediction of percentage lean in the side based on dissection of the rumpback joint and, if so, whether the dissection of any of five other sample joints would have been better.

For estimating lean content of the side, it was found that the lean content of any sample joint except the hand was a more precise predictor than standard carcass measurements alone, while including the latter in a prediction equation based on a single sample joint dissection improved precision further. For prediction based on lean in the sample joint alone, any one of the ribback, ham and rumpback was best. If other carcass measurements were included (in particular, C fat depth, eye-muscle area and trimming percentage were found to be useful), there was little to choose between the joints. For all joints there were differences between sire breeds (Large White, Canadian Yorkshire, U.S. Duroc, U.S. Yorkshire, Danish Landrace or Norwegian Landrace), sexes (hog or gilt) and feeding regimens (ad libitum or scale) in lean content of the side at constant lean content of the sample joint, but the regression slopes differed only when the rumpback or streak was used as a predictor, and then only between ad libitum and scale-fed pigs. It will therefore be important in any future such experiment fully to dissect a sample of each class (breed, feeding regimen and sex) to provide unbiased estimates of the differences in lean content. A sample of 30 from each class should allow the differences to be estimated adequately.

Motility characteristics of bull spermatozoa in mixed ejaculates of different bulls were compared with those of the unmixed samples after 40-to 50-fold dilution with clarified standard egg-yolk—citrate buffer (pH 6·80 ± 0·05 at 37° C., 6·75 ± 0·05 at 22–23° C).

Using the photo-electric equipment described by Rikmenspoel (1957b) and by Rikmenspoel & Van Herpen (1957) the mean velocity , the number of spermatozoa passing by a constant spot per time unit n, the total number of spermatozoa moving normally N, the velocity decrease with time ( — d/dt), the half-life period of the number of passages per time unit t½(n) and the half-life period of the total number of spermatozoa moving normally t½(N) were determined. For none of these characteristics was any statistical difference found between the actual results and the expected values based on calculation from the data obtained with the unmixed ejaculates.

Acid production was investigated by accurate determination of pH change on incubation of samples diluted ten times with standard egg-yolk—citrate buffer containing 736 mg. added fructose per 100 ml. Again there was no statistical difference between the values found with the mixed semen samples and the expected values.

It is concluded that differences observed by other authors must be due to the effect of environmental factors, i.e. to the semmal plasma, for which there is analogous evidence in human sperm physiology.

An investigation into the effects of lime on five acid soils in north-east Scotland has been continued during the second and third years after the application of lime and also extended to two other centres.

On four of the original soils the full effect of the lime on the surface soil has been largely maintained up to the end of the third year. The fifth, a soil of low base-exchange capacity, shows a considerable loss of lime by the end of the second year.

The lime leached from the top nine inches of soil appears to be retained to only a slight extent in the second nine inches. This was particularly noticeable on a soil of low base-exchange capacity, where, during the two years after liming, the percentage saturation of the subsurface soil showed an increase from 64 to 67%, and the surface soil a decrease from 92 to 74%.

The existence of a low liming factor (1·5), previously found to hold for a geologically basic soil, has been verified and found to apply also to a soil derived from slate.

A fundamental property of the soils with a low liming factor is the high content of inorganic and organic fine material. Secondary characteristics that distinguish these soils from the others are the relatively high values for hygroscopicity and heat of wetting.

The phosphorus status of 58 soil samples representing 15 soil series and four soil Orders (Ultisol, Entisol, Alfisol and Oxisol) in the major coconut-growing regions of Sri Lanka was evaluated by determining the available P extracted by the methods of Olsen, Bray & Kurtz No. 1, Bray & Kurtz No. 2 and NH4OAc (pH 4·8) and the various P forms. Total P in the soils ranged from 37 to 338 mg/kg with organic P and active P constituting only about 20 and 50% of the total P respectively. In general the sandy soils of the Entisols and Oxisols had lower total and organic P but higher active and available P than the rest. The relative abundance of the various inorganic P forms was generally in the decreasing order of inactive P, Fe-P, Al-P and Ca-P. Al-P and Ca-P were positively correlated with percentage sand and negatively correlated with percentage silt and percentage clay whereas total P and organic P had the opposite trend. Available P extracted by the four methods was very low in almost all soils except some of the sandy soils (Entisols) which had marginal to moderate P contents. They were positively correlated with Al-P, Ca-P, percentage sand and negatively correlated with percentages of silt, clay and organic carbon.

Phosphorus concentrations (0·074–0·116%) in the 14th leaf of coconut at the soil sites were all lower than the critical leaf-P concentration (0·120%). Leaf-P correlations with Bray & Kurtz No. 2-P and NH40Ac-P were significant (P < 0·05) and with Al-P and Ca-P were close to significant.

The study revealed that the coconut-growing soils of Sri Lanka were deficient in total as well as the active and available forms of P except perhaps some of the sandy soils of the Entisol. This was confirmed by coconut leaf P analysis.

To study the total-life performance of all the 156 sows, they were divided into groups consisting of sows having produced 73 to 77, 78 to 82, 83 to 87, … pigs throughout their breeding life often litters. The frequency distribution, of total number of offspring born, thus obtained is shown in Fig. 2.

Two maize hybrids, NHYB-1 and NHYB-2 with upright leaf orientation, and two composites, FARZ 27 and 34 with lax leaf orientation, were compared. The crops were grown at three levels of nitrogen (0, 75 and 150 kg N/ha) at Ibadan in the rain forest zone of Nigeria in 1979 and 1980.

N application increased leaf area index (LAI) and hastened flowering. The composites had greater LAI than the hybrids. Lodging was greater at harvest than at mid-silk and severer in the hybrids than in the composites. Grain, stover and total dry-matter yields were greater for the composites.

The hybrids were more responsive to N application in 1979 but the pattern was not consistent in 1980. More dry matter was partitioned to the grain in the hybrids as shown by their higher harvest index, especially in 1979. The concentration of N in ear leaf and stover increased with increase in N application, but P and K concentrations in the stover were highest in the control treatment.

Grazing with sheep was compared with cutting, in each case at three frequencies, four, five and six defoliations per year, on a lucerne—cocksfoot ley. The treatments were applied in one year and their effects measured during that year and at cuts in June and August of the following year. One experiment began in 1963 in the second harvest year of a ley and a second began in 1964, on an adjacent site, in the third harvest year of the ley. Cutting four times in the year allowed lucerne to persist satisfactorily in both experiments. In the 1964 experiment cutting five or six times and grazing rather than cutting had no apparent, serious, adverse effect on the lucerne compared with cutting four times. In the 1963 experiment, however, increasing the number of cuts and grazing rather than cutting had a large adverse effect on the lucerne, and in the most extreme treatment, grazing six times, the proportion of lucerne was reduced to 2 % of total herbage yield the following June compared with 66% on the four-cut treatment. The contrasting results in the two experiments seem associated with weather differences, 1964 being a much drier, more sunny growing season than 1963, and perhaps with the differences in age of sward, individual lucerne plants perhaps having bigger roots with more reserves in 1964 than in 1963. During the treatment year increasing frequency of defoliation tended to increase the N content of both species and grazing compared with cutting generally increased the N content of cocksfoot. During the year following the treatment year the N content of the two species was little affected by the experimental treatments. The implications for farm practice are considered.

Cotton (Gossypium hirsutum L.) yield and quality is affected by altered fruiting patterns with progress in season. The present study was conducted to analyse normal and altered (abnormal) boll (fruit) development at maturation phase. Both normal and abnormal bolls of the same age groups were analysed for growth in terms of dry weight, water content and endogenous abscisic acid (ABA) content of fibre and seed. Endogenous level of ABA was estimated by using antibodies raised against ABA–protein conjugate. To amplify the reaction, indirect ELISA (Enzyme Linked Immuno Sorbent Assay) was performed. A marked decrease in dry matter accumulation (DMA) of seed and fibre was observed in abnormal bolls as the season progressed. Fibre from the abnormal bolls showed marked variation in endogenous ABA content, however, in abnormal seeds water content and endogenous abscisic acid content showed significant variation compared to that of normal bolls. From the results, it is concluded that a marked decrease in seed dry weight may be because of a decrease in water content and accumulation of higher endogenous abscisic acid content, whereas, the major reason for reduced fibre weight may be due to accumulation of endogenous abscisic acid.

The relationship of efficiency to weight and feeding rate has been studied in 38 twin calves from 2 to 18 weeks of age. Following birth or weaning heavier animals were more efficient, but tended to be slightly less efficient when fully established on a diet. On balance, they possessed an advantage.

Heavier twins and heavier pairs were also on average more efficient. The increase in mean efficiency for contemporary animals was about 1% for each 1 lb. superiority in weight over the 4-month period. These results contrast with the well-known decline in efficiency as animals increase in weight. Different pairs declined in efficiency with increasing live weight at distinctly different rates judged by the resemblance of twin and co-twin, but evidence for genetic control was slight.

More efficient animals were associated with a relatively more rapid decline in efficiency, leading to a general convergence in efficiency as animals grew heavier.

The relationship of efficiency to feeding rate was very similar to the relationship with weight.

Three hundred and eighty-two Fayomi pullets were available from different hatches throughout the year. The age and body weight, as well as the weight of first eggs at sexual maturity in relation to growth curves, were recorded. The fertilizability and hatchability of the first eggs laid at sexual maturity were also examined from one hundred pullets hatched during the months of November and August.

1. (a) The winter hatches (December, January and February) reached sexual maturity at 183 days and at a body weight of 1093 g. The weight of the first ten eggs was 31·8 g., while the period from first to the tenth egg was 26 days. Summer hatches (June, July and August) reached sexual maturity at 165 days and at a body weight of 1124 g., while the weight of the first ten eggs was 32·4 g. and the period from first to tenth egg was 31 days. Autumn hatches (September, October and November) reached sexual maturity at 159 days and at a body weight of 1023 g., while the weight of the first ten eggs was 31·4 g. and the period from first to tenth egg was 23 days.

(b) Summer and winter hatches attained sexual maturity at an older age and heavier body weight, and laid heavier first ten eggs in a longer period than autumn hatches.

2. The growth curves were higher for the summer hatches than for the spring (March, April and May) ones. Winter and autumn hatches were intermediate. Summer hatches attained sexual maturity at a higher relative growth rate than autumn and winter hatches. In Egypt (30° N.), the effect of temperature seems to override that of daylength in respect to growth and sexual maturity.

3. Yearly differences in the attainment of sexual maturity were significant, mainly in December hatches. Individual differences were minimized during summer hatches.

4. (a) The first egg laid can be fertilizable and even hatchable. When sexual maturity was attained at an old age or a heavy body weight, the first eggs laid had a greater chance of being fertilizable and hatchable. This is due to the weight of first eggs laid and to the season at which sexual maturity is attained.

(b) The attainment of sexual maturity as measured by the fertilizability and hatchability of first eggs, seems to be a gradual phenomenon.

An investigation was made during 1988 to test the hypothesis that ‘Grasslands Huia’ white clover (Trifolium repens L.) could be eliminated under close sheep grazing. The effects of grazing management, topography and fertilizer on the contribution of Huia plants to the white clover population in an 85 ha experimental upland pasture ecosystem in the southern North Island, New Zealand (lat. 40° 20′ S, long. 175° 50′ E, 125–350 m altitude) were quantified 11 years after oversowing. Replicated sampling sites (108 in total) were located on nine combinations of slope and aspect within grazing management treatments comprising rotational grazing with cattle (RC), rotational grazing with sheep (RS) and continuous grazing with sheep (CS), with high and low fertilizer treatments in each case. White clover occurrence, leaf area, phosphoglucoisomerase-2 (PGI-2) allele frequencies and the proportion of Grasslands Huia plants in the white clover population were determined at each site. White clover frequency was lower on steeper slopes. Aspect, slope and grazing management affected area of individual clover leaves. The proportion of Huia plants in the white clover population averaged 54·9, 49·0 and 33·6% for RC, RS and CS, respectively (P < 0·039, 5 D.F.). Fertilizer and topography did not affect the proportion of Huia. It was concluded that although Huia did persist after 11 years of close sheep grazing, its contribution to the total white clover population was unsatisfactory in some cases, and use of better adapted cultivars is suggested.

An experiment comparing continuous winter wheat with the two wheat crops in a rotation of beans, oats, wheat, wheat, with four rates of application of N fertilizer, is described and the results discussed.

The wheat following wheat in the rotation consistently outyielded the wheat following oats, but the continuous wheat yielded on average less. Response to N fertilizer was not affected by sequence of cropping and since there was practically no response to the highest increment of N, it is clear that additional N could not have brought the yield of the continuous wheat up to the level of the wheat in rotation.

The effects of season and altitude on floral initiation of two Trifolium repena L. cultivars, Haifa and California Ladino, were tested in the area of Ayacucho, Peru (2730 m, 13° S), with regard to their seed production potential. Specific effects of daylength at a constant temperature (20 °C) were examined in growth chambers.

In Ayacucho, the proportion of inflorescence-bearing nodes was found to be lowest between December and June (Haifa 10–20%, Ladino 0–10%) and highest in August (Haifa 30%) and September–October (Ladino 15%). Late in the cool season, floral initiation of Ladino, but not that of Haifa, increased strongly at a high altitude (3250 m). In growth chambers, Haifa initiated few inflorescences and Ladino none in a 10 h daylength. In 16 h, the floral initiation of Haifa was very limited but Ladino formed many inflorescences. Floral initiation of Haifa was most pronounced and lasted longest after a daylength shift from 10 to 13 h.

It is concluded that seasonal and altitudinal variations in low temperature were the main factors influencing floral initiation in the region of Ayacucho. Haifa is considered to be an intermediate-day plant, suited for seed production in the region because of its marked and early flowering. Ladino was classified as a quantitative longday plant, unsuitable for seed production at this low latitude because of its retarded floral response to low temperature.

The investigations described in the present paper are based on the records of the dairy herd at the farm of the University College of North Wales, at Aber near Bangor. The results obtained will have a more definite significance if some account is given of the nature and management of that herd.

The Bangor provincial area, including the four Northern Counties of Wales, is roughly divided into Welsh Black and Shorthorn country by the Conway River. Most of the cattle in Anglesey and Caernarvonshire are of Welsh Black type, and the ordinary non-pedigree dual purpose type of Shorthorn predominates in Denbighshire and Flintshire.

Field studies were conducted at Ilorin and Bacita during the 1985–6 cropping season to evaluate the use of hexazinone [3-cyclohexyl-6-(dimethylamino)-l methyl-1, 3, 5-triazine-2, 4(1 H, 3H)-dione] alone, and in combination with diuron [3,(3,4-dichlorophenyl)l-l dimethyl urea] in crops of sugar cane. Hexazinone, alone or in combination with diuron, effectively controlled a broad spectrum of weeds in a loamy sand soil at Ilorin. Most of the herbicide rates used were, however, severely phytotoxic to the crop. On silty clay-loam soils at Bacita, the same herbicide treatments, while giving effective control similar to that obtained at Ilorin, were not phytotoxic to the crop. Weed control effectiveness was influenced by the percentage of organic matter in the soils and by the amount of herbicides used. A broader spectrum of weeds was controlled by the mixture of hexazinone plus diuron than by hexazinone alone. There was no difference between the performance of the tank and formulated mixtures of hexazinone plus diuron.