Foliar tissue norms were developed for 'Apollo' alfalfa (Medicago sativa L.) grown on two highly weathered soils in the Georgia Piedmont for use in the diagnosis and recommendation integrated systems (DRIS). These norms were generated from a data bank comprised of tissue nutrient composition and plant yield and consisting of 3915 field observations. A yield of 3.5 Mg ha-• per cut was used to divide high yielding from low yielding members. Norms were generated by averaging values from the high yielding segment for all possible ratios of N, P, K, Ca, Mg, Zn, Cu, B, and dry matter (DM) and compared to those previously calculated from midwestern data. Values from Georgia were generally similar to those from the Midwest, except for Mg, which was lower, and B, which was higher. Differences in Mg norms were attributed to soil conditions. Norms generated in Georgia correctly diagnosed nutrient requirements of plants grown in Georgia, but differences between the two sets of norms indicate some regionality in DRIS norms for alfalfa. The DM index was demonstrated to adequately separate nutrients present in sufficient and insufficient quantities for recommendation purposes.

The relationships between fly ash application to soil and B availability under field conditions were studied over a 3‐year period. The two fly ash samples studied contained 232 and 370 ppm of total B. Incorporation of one application in 1971 of either fly ash sample into a Tatum silt loam increased alfalfa (Medicago sativa L.) yield over a 3‐year period. Yield increases were attributed to an alleviation of B deficiency. Boron uptake data indicated that B in the fly ash samples was readily available initially but decreased with time. Results of correlation and regression analyses suggested that hot‐water‐soluble B extractions could be used to predict plant availability of B in fly ash‐soil mixtures.

Notwithstanding a voluminous body of literature on the subject there is still poor agreement regarding the relative merits of lime requirement indices based on exchangeable Al and those based on pH measurements. The work reported here was conducted in an effort to obtain greater clarity on the subject. Lime × P × Mg factorialized pot experiments were conducted on Mollisols, Ultisols, and Oxisols using corn as an indicator crop. Plant tissue was analyzed for several essential elements plus Al and the soils were tested for exchangeable cations, P, and pH. Yield responses fell into three categories: (i) those in which liming neither promoted nor depressed growth, (ii) those where growth was initially promoted by liming with no depressive effect and (iii) those where liming to neutral pH values depressed yield. The results showed that corn response to lime was essentially similar over a wide range of soils when Al saturation of the soil was used as the index of lime requirement. Corn response was poorly related to pH in water but the relationship improved when salt pH was used. As nearneutral pH values were approached, the uptake of a number of nutrients was reduced, suggesting that the long‐held view that such pH values have beneficial effects on nutrient availability warrants re‐investigation.

Field investigations were i n i t i a t e d in 1971 to s t u d y t h e effect of a weat h e r e d fly ash sample on yield a n d n u t r i e n t c o n c e n t r a t i o n of corn (Zea mays L.) a n d on composition of displaced soil solutions, a n d to d e t e r m i n e rates of fly ash t h a t could be applied to soils w i t h o u t adversely affecting p l a n t growth. Application of w e a t h e r e d a s h at rates r a n g i n g from 18 to 288 metric t o n s / h a did n o t decrease corn grain yields on either Groseclose silt loam or Woodst o w n l o a m y fine sand. Corn grain yields were increased on t h e W o o d s t o w n soil in 1972 where c u m u l a t i v e rates of 216 a n d 288 metric t o n s / h a of fly ash were applied, which was a t t r i b u t e d in p a r t to increased soil moisture. P l a n t analysis d a t a i n d i c a t e d t h a t B a n d M n c o n c e n t r a t i o n s were not increased to toxic levels as h a d been r e p o r t e d in o t h e r investigations w i t h u n w e a t h e r e d fly ash. Soil solution d a t a verified t h a t toxic a m o u n t s of these elements were n o t released from t h e w e a t h e r e d a s h sample.Calcium c o n t e n t of displaced soil solutions was increased b y fly ash application b u t was n o t sufficiently high to effect increases in Ca c o n t e n t of corn tissue. T h e d a t a suggest t h a t t h e w e a t h e r e d fly ash u n d e r s t u d y could be applied to soils at c u m u l a t i v e rates of 288 m e t r i c t o n s / h a w i t h o u t inimically affecting crop growth.