The effect of nitrogen, phosphorus, and potassium supply on the isoflavone content of leaves of red clover (trifolium pratensel.)

1967 ◽  
Vol 10 (2) ◽  
pp. 312-315 ◽  
Author(s):  
G. W. Butler ◽  
M. A. Th. Steemers ◽  
E. Wong
Author(s):  
A. G. Gurin ◽  
S. V. Rezvyakova ◽  
N. Yu. Revin

The study aimed to estimate seasonal dynamics of soil nitrogen, phosphorus and potassium under the influence of sod grasses in a sod-dressing intercropped orchard. The trial was conducted in a Welsey apple 1987-year orchard. Trees were planted at 8×6 m, cultivar seedlings used as rootstock. Red clover and meadow timothy in variant shares were used for interrow sodding. The cereal—legume intercropping was done in 2015, preceded by a 180 kg/ha active substance phosphorus-potassium dressing in reserve. Nitrogen was applied annually prior to growing season at 34.4 kg/ha active substance. Grass biomass in first hay cutting was the highest and comprised 45.3-49.9 % total mass. A total four cuttings dry mass was 3.36-7.10 t/ha depending on scheme. The maximum biomass was registered for the schemes with red clover and meadow timothy at ratios 1:1 and 7:3 (6.52 and 7.10 t/ha). In the growing period, grass depleted soil for 111.1—219.9 kg/ha nitrogen, 21.5-42.7 kg/ha phosphorus and 209.3—380.8 kg/ha potassium. Such consumptions suggest a serious competition for soil nutrients between grass vegetation and fruit trees. The available phosphorus and potassium content was independent of interrow dressing schemes. Inter-scheme differences did not exceed experimental bias due to presowing phosphorus and potassium application in reserve before trial. By first cutting, the nitrate nitrogen soil content in sodding schemes was 1.5-2-fold less vs. bare fallow, i.e. more nitrogen is used by vegetating grass, and its available forms recover slower than being consumed.


1957 ◽  
Vol 37 (3) ◽  
pp. 220-236 ◽  
Author(s):  
R. W. Shuel

The influence of mineral nutrition on nectar secretion both per se and in relation to certain aspects of growth and development was studied in snapdragon and red clover plants growing in sand culture. Snapdragon was grown at two levels each of nitrogen, phosphorus, and potassium, red clover at three levels each of phosphorus and potassium. The volume of nectar and weight of nectar sugar secreted per inflorescence were affected by the supply of each of the elements studied. Secretion in snapdragon was favoured by the lower levels of nitrogen, phosphorus, and potassium. Secretion in red clover was best at the low and intermediate levels of phosphorus and at the intermediate level of potassium. Although a high concentration of phosphorus or potassium in the mineral supply reduced secretion in both species, the threshold concentration for this inhibitory effect was higher in red clover than in snapdragon. High concentrations of potassium consistently reduced the sugar concentration of the nectar in both species. Flower number as well as quantity of secretion per inflorescence varied with nutritional treatment. For maximal production of nectar by the plant, the following conditions of fertility would appear desirable: A level of nitrogen low enough to avoid excessive vegetative growth, a level of phosphorus sufficient to promote good flowering, and a level of potassium which is neither low enough to limit growth severely nor high enough to reduce flower production.


1957 ◽  
Vol 10 (1) ◽  
pp. 57 ◽  
Author(s):  
DW Goodall ◽  
WG Slater ◽  
AE Grant Lipp

In a sand� culture experiment with lettuces, the water content (as per cent. of dry matter) of the aerial portions was studied in plants subjected to five levels of nitrogen, phosphorus, and potassium supply in all combinations.


HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 603E-603
Author(s):  
Bielinski M. Santos ◽  
Jose P. Morales-Payan

Studies were conducted in the Dominican Republic to determine the short-term response of young `Cartagena Ombligua' papaya (Carica papaya) plants to nitrogen (N), phosphorus (P), and potassium (K) fertilization. N, P2O5, K2O were individually applied 20 days after transplanting at rates 0, 6, 12, 18, and 24 g per plant. Plant height, stem diameter, leaf area, and root and shoot dry weight responded to N and K in a quadratic fashion (N:Y= 30.79+ 1.35X-0.07X2; K20:Y = 30.02 +1.6X - 0.06X2). Maximum growth was obtained with 6 and 18 g of N and K2O, respectively. P fertilization did not significantly affect shoot growth, but it stimulated root growth (Y = 2.02 + 0.41X - 0.013X2).


2010 ◽  
Vol 36 (4) ◽  
pp. 655-664 ◽  
Author(s):  
Yong-Jian SUN ◽  
Yuan-Yuan SUN ◽  
Xu-Yi LI ◽  
Rong-Ping ZHANG ◽  
Xiang GUO ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document