Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Abstract Only
Publication Acceptance Date: 10/2/1995
Publication Date: N/A
Interpretive Summary: White wheat was grown in three tillage systems with six fertility regimes to seek better methods to diagnose nutrient deficiency in cereal grain. Correct identification of individual element deficiency is difficult because visual symptoms of nitrogen, sulfur, and phosphorus in small wheat plants is quite similar. Wheat vegetative and grain response to fertilizers containing nitrogen alone, nitrogen plus sulfur, and nitrogen plus phosphorus was determined and compared to element concentration in plant tissue at tillering. All three elements increased crop yield when wheat was grown every year, but only nitrogen and phosphorus increased yield when the land was fallowed for one year before cropping. Comparing the nitrogen to sulfur ratio was a reliable method to identify sulfur deficiency. But nutrient concentration and element ratios were much less accurate for identifying nitrogen and phosphorus deficiency. Multiple-element ratio comparisons using a program called DRIS were highly influenced by the standards used for calibration. Detailed records of cropping history, soil fertility, past fertilizer use, and the type of crop grown appear necessary to augment analytical analysis of plant tissue when identifying nutrient deficiency. Technical Abstract: White wheat was grown under three tillage systems and six fertility regimes to improve plant analysis techniques for identifying nutrient deficiency. Wheat was grown on a field soil deficient in nitrogen (N), sulfur (S), and phosphorus (P), the major
Technical Abstract: White wheat was grown under three tillage systems and six fertility regimes to improve plant analysis techniques for identifying nutrient deficiency. Wheat was grown on a field soil deficient in nitrogen (N), sulfur (S), and phosphorus (P), the major nutrient deficiencies encountered in most wheat production areas. Tillage systems included no- till annual crop, conventional-till annual crop, and conventional-till wheat after fallowing. Fertility regimes included no fertilizer, N only, N+S, and N+S+P. Plant tissue samples were collected at tillering and at harvest for dry matter yield and element concentration. Grain yield was determined at harvest. The elements N and P increased grain yield in all tillage systems, while S increased yield only in annual cropping. Elemental concentration at tillering was not highly effective for identifying individual nutrient deficiency. Of element ratios, only the N/S ratio was an effective tool for identifying S deficiency. Multielement ratio analysis using the DRIS system failed to rank deficiencies correctly in some instances. Using a set of norms developed for hard red wheat was not as reliable as using a set of norms for white wheat. DRIS indices using white wheat norms underpredicted N deficiency and overpredicted S deficiency. DRIS indices using red wheat norms overpredicted N deficiency and underpredicted P deficiency. Complete crop and soil history appear necessary to augment plant tissue analysis when diagnosing nutrient deficiency in white wheat.