ÃÞ »¨ ѧ ±¨ Cotton Science 2009£¬21(4)£º290-295
Characteristics of Salinity and Fertility in Coastal Saline Cotton Fields in Shandong and Their Effects on Cotton Emergence Abstract£ºSoil samples (0-20cm ) from 318 saline cotton fields randomly selected in the Yellow River Delta were used to study the characteristics of salinity,contents of organic matter and major nutrients.The results showed that,of the total 318 saline fields tested,the lightly salty (LS) fields (salt content < 2.5g¡¤kg-1),moderately salty (MS) fields (2.5-4.49g¡¤kg-1) and severely salty £¨SS£© fields (> 4.50g¡¤kg-1) accounted for 44.3%,40.6% and 15.1%,respectively. The levels of N,P,K in MS fields were moderate,but K level in LS fields was low. The contents of organic matter,N and P were deficient,but K content was abundant in SS fields where cotton had been planted shorter than 5 years.In contrast,the contents of organic matter,N and P were moderate,but K content was relatively low in SS fields where cotton had been planted longer than 5 years.Regression analysis showed a significant linear correlation between soil salt content (y) and soil solution conductivity (x) at 25¡ã§³(y=3.4058x+ 0.1427,n=27,R2=0.9964**). Normal emergence and stand establishment rates were obtained when soil salinity was lower than 2 g¡¤kg-1. Rates of emergence and stand establishment were reduced to 60%-78% and 45%-55%, respectively,when salinity was 2-3g¡¤kg-1.The emergence and stand establishment rates were only about 40% and < 30%,respectively,in saline fields with salinity higher than 4g¡¤kg-1.Reasonable agronomic measures for stand establishment and chemical fertilization should be taken according to the characteristics of salinity and fertility,to improve cotton productivity in saline fields.
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