The yield and composition of kale and cabbage with and without nitrogenous top-dressing

In 4 consecutive years, 1948 to 1952, combined varietal and manurial trials were carried out to obtain information on the yields of marrow-stem kale, thousand-head kale and cattle cabbage in the presence and absence of sulphate of ammonia applied as a top-dressing at the rate of 6 cwt./acre.Yield and composition of all crops were apparently affected by differences in weather conditions. In most years, and particularly for cabbage, the yield declined with successive harvests.Increased green crop, dry matter and crude protein yields resulted from the application of nitrogenous fertilizer in 3 years, but in the other year, a very dry season, the response to the top-dressing was negligible.Marrow-stem kale both with and without the additional fertilizer, yielded more, in terms of fresh crop, dry matter and crude protein, than thousandhead kale with the same manurial treatment. Cabbage yields often approached those of marrowstem kale at the first harvest, but were nearer to those of thousand-head by the last harvest of each year.

Composition of the Nitrogen Fraction of Apple Tracheal Sap

Organic nitrogenous compounds accounted for most of the nitrogen present in apple tracheal sap. Aspartic acid, asparagine, and glutamine were quantitatively the most important compounds. Glutamic acid and other amino acids were also present as well as a peptide-like substance. While apple variety, rootstock, or manurial treatment may have had effects on level of nitrogen in tracheal sap they seem to have had little effect on proportions of nitrogenous compounds present. Through the growing season, however, there was a definite change in proportions of some of the constituents. The composition of the soluble� nitrogen fraction of leaves and fruits showed distinct differences from the composition of tracheal sap.

Some effects of fertilizer interactions on growth and composition of the potato plant

1. An account has been given of the percentages of nutrients in the dry matter and weights of nutrients in tops, tubers and roots of potato plants throughout growth under six fertilizer treatments.2. Manurial treatment affected dry-matter content of tops but not of tubers.3. Balanced manuring, as represented by N2PK treatment, resulted in tubers in which nitrogen content of dry matter declined with age. The effect of the K was to lower the nitrogen, phosphorus and calcium contents, to increase chlorine content of all parts of the plant, and to maintain a much higher and more constant concentration of potassium in tops and roots. With unbalanced manuring the nitrogen content of the tubers was more constant.4. Manuring with nitrogen only raised the content of potassium in the dry matter of all parts of the plant.5. Nitrogenous manuring, whether alone or in combination, raised the nitrogen content of the dry matter of all parts of the plant, a smaller proportion of which was present as protein. Calcium and chlorine contents were lowered.6. Phosphate manuring in conjunction with nitrogen depressed the concentration of potash in the dry matter of all parts of the plant.7. N2P plants were the first to attain their maximum uptake of all nutrients, namely, about 7 weeks from appearance above ground, at which time N2PK plants had absorbed only 40% of the quantities finally noted.8. No losses of elements were observed in the plants which received balanced manuring (N2PK), but losses of calcium and chlorine occurred in all other plants, amounting on the average to 25 and 37% respectively, but being highest in N2P plants. A significant loss of potassium occurred in N2 plants and a highly suggestive loss of phosphorus occurred in N2P plants.

The influence of manurial treatment on the carotene content of poor pasture grass, and on the relationship of this constituent to the ash and organic Fractions

Sulphate of ammonia and nitrate of soda, applied at monthly intervals, produced increases in the carotene content of poor pasture grass amounting to 28%. Sulphate of potash, also applied monthly, produced an increase of 6·2%. A single dressing of carbonate of lime, which was sufficient to satisfy the lime requirement of the soil, produced no effect on carotene content, whilst monthly dressings of superphosphate also had no influence except in the month of June, when an increase of 14·5% was produced. All five manurial treatments significantly increased the yields of dry matter and carotene.Carotene contents were very low during the drought experienced in April and May 1938, increased significantly in June, and showed very marked and highly significant increases in the autumn months.Ash content was increased by the three non-nitrogenous manures, and protein content by nitrate of soda, sulphate of ammonia and superphosphate. Ether extract was increased by superphosphate and sulphate of ammonia, whilst nitrogen-free extract was decreased under all manurial treatments except carbonate of lime. None of the five artificial fertilizers had any effect on the mean fibre content of the grass, although various significant differences were observed on certain sampling occasions. Normal seasonal variations occurred in the percentages of ash and organic constituents.Correlations of carotene with crude protein, fibre, nitrogen-free extract and ash have been computed for each manurial treatment and several significant differences have been observed. The physiological significance of these correlations has been briefly discussed.

The growth of clover in the presence of ammonium sulphate

It has long been held that the treatment of grassland with nitrogenous fertilizers, and especially with ammonium salts, reduces the clover content. This method has been applied also to the treatment of lawns and sports fields with a view to reducing the clover content of the turf. It has been suggested that the effect of the ammonium salts is to encourage the growth of the grass in competition with the clover, and also that the ammonium ions are specifically toxic to the clover plant. Since there is a growing volume of evidence that ammonium ions are, in fact, available to many plants and may be used by them directly, without nitrate-formation, it was thought desirable to examine the effect of the application of ammonium sulphate to clover plants grown in pots, where competition from grasses was not a factor in the consideration of the effect of manurial treatment.