38 EXPERIMENT STATION RECORD. 



Water content of soil and nitrog'en fertilization in relation to the develop- 

 ment of Gbttingen bearded square-head winter wheat in different vegetation 

 periods, K. SIeyer ( Ucber den FJin/Iiiss verschiedcn hohen Wassergehalts des 

 Bodens in den einzelnen Vcr/ctationsstadicn bie vcrschiedener N-Bungung auf 

 die Entiviickehtng des Gottinger iegrannten Squarehead-Wintenceizens. Tnaug. 

 Diss., Univ. Qottingen, 1908. pp. DO, pis. 3). — These tests were conducted in zinc 

 pots 33 cm. high and 25 cm. in diameter. Each contained 20 kg. of soil to which 

 had been added 1 gm. of potash in potassium carbonate and 1 gm. of phos- 

 phoric acid in monocalcium phosphate. To some 1.5 gm. of nitrogen in nitrate 

 of soda was added, and to others only 0.5 gm. of nitrogen. The water content 

 of the soil was maintained at 45 per cent of its absolute water-holding capacity 

 during the first vegetation period, and at TO per cent during the rest of the test. 

 In other cases this order was reA'ersed. 



From the data presented the author draws the following conclusions: The 

 water consumed is less in case of high nitrogen fertilization, and high water 

 content of the soil markedly increases the total yield only in case much nitrogen 

 is present. The ratio of grain to straw is reduced by the presence of a large 

 amount of moisture if plant food is not present in sufficient quantity. Grain 

 formation is favored by an increase in the amount of water present during the 

 last vegetation period. 



Tillering is influenced by nitrogen fertilization and the amount of water 

 present. The weight of the roots is increased by nitrogen fertilization and by 

 an increase in the amount of water present, but the same root mass will produce 

 more grain and straw on a fertile soil than on a thin soil. The total length 

 of haulm depends generally on the water content of the soil during shooting. 

 Tillering is unfavorable to length of haulm only when the soil is deficient in 

 plant food. Potash fertilization does not determine the relative length of 

 internodes and haulms. The length of the upper internode is influenced by 

 the water content of the soil, particularly at the time of shooting, while the 

 length of the lower internodes depends on the water content during the first 

 vegetation period. Abundant fertilization and soil moisture increase the 

 strength of the straw and weight of head. Tillering reduces strength of straw 

 and weight of head only when accompanied by lack of plant food. The water 

 supply during the first vegetation period governs the length of hea5°irncrTEe 

 numlier of kernels per head. Barren spikelets result from unfavorable water 

 and food conditions. Increased moisture at the time of shooting gave the 

 lowest number of barren spikelets in the case of high nitrogen fertilization. 



Nitrogen fertilization rather than the water content of the soil appeared to 

 be of importance in determining the number of blossoms per spikelet; it also 

 favored symmetry of head. The less nitrogen there is available the more the 

 soil moisture influences symmetry of head. In case of change in the amount 

 of water, only a high moisture content during the first period exerted an un- 

 favorable influence on the symmetry of head. 



Other things being equal, the length of beard increased with length of head. 

 Insufficient moisture during the first vegetation produced long beards, but much 

 moisture produced a weak development of beard. There ai)]ieared to be no 

 constant relation between length of beard and weight of grain. The jpilgest 

 beards appeared higher on the head than did the heaviest kernels. 



With low nitrogen fertilization the heaviest kernels appeared in the lower 

 portion of the ear, while high nitrogen fertilization apparently lesulted. in a 

 tendency for the heavy kernels to appear at the middle of the head. The 

 1 ,000-lternel weight varied with the soil moisture in case of the heavier appli- 

 cation of nitrogen, Plant food was low if much moisture was applied at an 



