FIELD CHOPS. 129 



clover plant. The water requirements of rye were much less than those of 

 wheat. Clover used the soil water most freely and left the soil in dry condition, 

 while the potato, among the crops grown, used the smallest quantity of soil 

 moisture and left the subsoil comparatively moist. Peas were found to be low 

 in water requirement and oats high. 



In the study of a number of varieties of wheat it was observed that the soil 

 moisture content was capable of influencing the ripening period to such an 

 extent that varietal characteristics in this regard were entirely lost. On soil 

 containing 55 per cent of moisture there was little difference in the ripening 

 period of 4 different varieties of spring wheat, but on soil with more moisture, 

 and especially where a water content of 70 per cent was maintained, the 

 differences in the period of matui'ity were quite marked. 



Observations on the root development of crops grown alone or in mixtures, 

 H. Kasekek (Ztschr. Landiv. Versuchsw. Osterr., 14 {1911), i\o. S, pp. 1022- 

 1030). — A discussion is presented on the excretion of substances of an organic 

 nature by the root systems of plants, and the results of observations on the 

 development of the root systems of crops grown singly or in mixtures are 

 reported. 



Rape and turnips in all cases were of tap-root formation and gave little 

 or no indication of being influenced in root development by other crops grown 

 with them. A mixture of rye and barley showed considerable interweaving of 

 the roots with a tendency to development near the surface of the soil. Peas 

 and vetch grown together also were shallow rooted and the matting of the roots 

 was light. The growth in a mixture of a gramineous and a leguminous crop 

 always showed good matting of the root systems and this was especially true 

 with barley and vetch and barley and peas. Here the matting was so perfect 

 that no single plant could be separated from the mass without tearing the roots. 

 Flax sown thickly and grown alone was inclined to form tap roots, but grown 

 in mixtures the roots formed many laterals and when sown with barley, rye, 

 peas, and vetch considerable matting took place, especially with vetch and rye. 

 The most densely matted root systems were found where the 7 different crops 

 entering into the experiment were grown in one mixture. 



The conclusion is drawn that in pure culture of a crop the development of 

 the roots of any individual plant is influenced by the growth of the roots of 

 the individuals near it, and that this tends to bring about deeper root growth, 

 while in the case of mixed culture, especially when the plants are not closely 

 related to each other and in case sufiicient moisture and plant food are avail- 

 able, each crop develops its root system as if it alone occupied the ground. 



Fertilization of oil-producing crops, G. Ramnek (Ratsion. Udobr., 1910, No. 

 9; nbs. in Zhiir. Opijtn. Agroii. {Russ. Jour. Expt. Landic), 11 (1910), No. 6, 

 pp. 865, 866).— Experiments were conducted in the Poltava government, Russia, 

 with applications of 32 tons of barnyard manure per acre as compared with 

 the use of 16 tons, the customary quantity used. 



It was found that the heavier application increased the yield of poppy seeds 

 by 40 per cent, the yield of summer rape seeds by 10 per cent, and the yield 

 of straw of summer rape by 16.7 per cent. Doubling the amount of manure 

 did not increase the yield of sunflowers materially. The hea^T manuring in- 

 creased in all cases the yield of hemp to a considerable extent, but the per- 

 centage of fiber in the crop was less than where only the ordinary amount of 

 manure had been used. 



As a rule, plowing to a depth of 9 in. gave much better results than plowing 

 5 in. deep. Flax, however, gave a better yield on the shallower plowed land. 

 Flax gave a better yield when grown after clover than after rye. 



