| In order to make clear the water conserving effects of different water holding
materials and to relief the restriction of water shortage on seedling growth of
maize in dry farming area, the experiment was conducted in Qingshuihe County, I
nner Mongolia. There were 5 treatments including PAA(A1), PAM(B1), humic acid(C1
), bentonite(D1) and control(CK) in 2011, and 8 treatments including A2, B2,
C2, A1, B1, C1, D1 and CK (1 meant that the water holding materials were appl
ied in only one year, while 2 meant that they were applied continuously in two y
ears) in 2012. The effects of these materials on water conserving ability of soi
l as well as seedling growth and yield of maize were analyzed. The results showe
d that, in 2011, the overall effect of the treatments was ordered as: A1>B1>D1>C
1>CK; the water holding materials could increase the emergence rate and shorte
n the emergence time of maize by 1～2 days. In 2012, all water holding material
s promoted the seedling growth of maize and the water conserving ability of soil
, and the overall effect of the treatments was ordered as: A2>B2>C2>D1>A1>B1>C1>
CK. Compared with CK, the emergence rate of maize under A2, B2, C2, D1, A1, B1
and C1 increased by 9.87%, 7.28%, 5.71%, 5.41%, 4.41%, 3.13% and 1.26%, resp
ecti
vely; the daily increment of plant height increased by 15.67%, 14.93%, 13.43
%, 1
1.94%, 11.94%, 8.21% and 0.00%, respectively; the fresh weight increased by 38.8
4%, 34.52%, 28.80%, 25.17%, 21.93%, 13.67% and 2.48%, respectively; the soil
wat
er storage in 0～20 cm during seedling stage increased by 30.07%, 28.16%, 16.26%
, 15.62%, 8.50%, 7.97% and 2.34%, respectively; and the yield of maize increased
by 25.15%, 22.45%, 19.05%, 15.05%, 14.17%, 12.88% and 5.37%, respectively. Cons
idering all the indexes and the annual changes comprehensively, the overall effe
ct of D1 was better than that of A1, B1 and C1, and its effect was more persiste
nt. |