masi eng 47,044 اشتراک گذاری ارسال شده در 28 مرداد، ۱۳۹۳ [h=3]Introduction[/h] Studies have been conducted periodically over the years in Illinois on the need of zinc (Zn) by agronomic crops. However, an in–depth evaluation of the need for and response to zinc by corn and soybean has not been conducted in southern Illinois for over 24 years. The last intensive survey and study throughout Illinois was conducted in 1977 to 1979 in which a total of 85 sites were evaluated, including about 20 sites in southern Illinois (Brinkman et al., 1980). In these statewide studies only three sites responded significantly to applied zinc and only about one-fourth of the sites responded economically positive to the zinc treatments. Because tillage practices have changed, higher yielding varieties and cultivars have been introduced, and appreciable quantities of soil zinc have been removed in harvested crops without replenishment, a re-examination of the fertilizer zinc needs of corn and soybean is warranted. In addition reports from commercial laboratories suggest that an increasing number of soil and plant tissue analyses are marginal with respect to zinc sufficiency. برای مشاهده این محتوا لطفاً ثبت نام کنید یا وارد شوید. ورود یا ثبت نام (240.0 کیلو بایت) برای مشاهده این محتوا لطفاً ثبت نام کنید یا وارد شوید. ورود یا ثبت نام نقل قول لینک به دیدگاه
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