Foliar diagnosis of soybean by dris

Abstract

The Diagnosis and Recommendation Integrated System (DRIS) has proven useful in the interpretation of tissue elemental analyses for many crops, and research was undertaken to apply the same method for foliar diagnosis of soybean (Glycine max [L.] Merr.). Using a data bank in excess of 3500 tissue samples, reference values for evaluating the status of soybean with respect to N, P, K, Ca, Mg, Mn, Fe, Cu, Zn, Mo, B and Al were derived. DRIS diagnoses generally agreed with those obtained by the sufficiency range method. In addition, DRIS assessed the nutrient balance in plant tissue, and identified not only the most‐limiting element, but the order in which other elements would likely become limiting. Further, DRIS was able to diagnose plant nutrient needs earlier in the life of the crop than the sufficiency range method (5 weeks compared to 10 weeks), which would allow remedial steps to be taken earlier. Treatments indicated by DRIS to be needed gave greater yield increases than those indicated by the sufficiency range approach. Geographic differences in DRIS norms were identified, and indicate that regional derivation of diagnostic values may be necessary.     

Interrelationships between growth and nutrient uptake in alfalfa and corn

Nutrient requirements o£ plants during their various phases of growth are affected by several internal and external factors. The changes in rate of uptake by root with age are an important factor to meet the increasing plant demand for nutrients. Nutrient culture experiments were carried out under controlled greenhouse conditions with corn (Zea Mays L.) and alfalfa (Medicago sativa L.) to investigate the relationship of stage of growth to changes in plant parameters and nutrient uptake properties. With advancement of age. both plant species increased their ambient growth medium pH towards neutrality. With increasing age in alfalfa there was very little change in observed S:R ratio and root growth rate. On the other hand in corn plants the S:R ratio increased and growth rate for root and shoot decreased with age. Alfalfa contained higher concentrations of N, K, Na, and Ca than corn; while ion concentrations in both crops decreased with plant age. At all stages of growth, alfalfa absorbed less nutrients than corn. The rates of nutrient influx, I_n in both the crops showed various degrees of correlation with age and rate of shoot growth. In corn. I_n for ions reached a maximum at 25 days growth; whereas, in alfalfa, I_n reached maximum at 30 days of growth. The differences in influx rates for different ions in the two species are probably due to the difference in development of shoot and root parameters and shoot demand for the ions.     

Tomato growth and nutrient uptake patterns as influenced by nitrogen form and light intensity 1

Tomato plants were grown in sand culture with NH₄ or NO₃ forms of N and at two levels of light. Plants were harvested at 0, 5, 9, or 12 days after starting treatments. NH₄‐N nutrition reduced growth, suppressed K, Ca, and Mg accumulation in shoot, increased P and N content and markedly reduced K, Ca, and Mg uptake per unit of root surface. Reduced light level decreased the toxic effects of NH₄ and markedly decreased NH₄ accumulation in shoots.     

Role of continuous nitrogen fertilization on nutrient composition of leaves sampled at various stages of growth and on yield of yam (Dioscorea rotundata)

Abstract

White yam (Dioscorea rotundata cv. Olonko) was grown consecutively for three growing seasons, i.e. from February to October of 1975, 1976 and 1977, and treated with six levels of nitrogen, viz: 0, 40, 60, 120, 160 and 200 kg N/ha in the field. Leaf samples were taken at four stages of growth as follows: vegetative, tuber formation, tuber development and tuber maturation, and analyzed for NO₃‐N, P, K, Ca and Mg.

Increasing nitrogen fertilization consistently increased leaf‐NO₃‐N, particularly at the vegetative stages of growth, while no consistent trend was established for leaf‐P. Leaf‐K was increased at low rate of nitrogen fertilization during tuber formation and maturation whereas leaf‐Ca increased only at tuber maturation in the presence of higher rates of nitrogen fertilization. There was a marked increase in leaf‐Mg at all stages of growth when N treatment was increased to 200 kg N/ha. A positive correlation (r = 0.84???) was obtained for leaf‐K at the vegetative growth stage with tuber yield, while leaf‐Mg was positively correlated with tuber yield at vegetative (r = 0.46?), tuber formation (r = 0.50?) and tuber development (r = 0.67??) stages. All other elements were negatively correlated with yield at all stages of growth. Tuber yield was highest at the 200 kg N/ha treatment.     

Tomato growth and mineral composition as influenced by nitrogen form and light intensity

Abstract

Tomato plants were grown in sand culture with NH⁺ ₄, and NO^? ₃, forms of N and three levels of light. Plants supplied with NH⁺ ₄, nutrition under high light intensity had symptoms of stunting, leaf roll, wilting, interveinal chlorosis of the older leaves, and one third the dry weight of N0₃‐fed plants. In contrast, growth of plants receiving NH⁺ ₄, nutrition under shade appeared normal although dry weight was reduced. NH₄‐N nutrition suppressed K, Ca and Mg accumulation in tissues and increased P contents as compared to NO₃‐N nutrition.     

Growth and nutrient interrelationships of three vegetable crops with different sensitivities to soil pH as affected by lime and fertilizer treatments

Abstract

In seeking reasons for differences in sensitivity among vegetables to low soil pH and the roles of lime and fertilizers, an experiment was conducted in 1984 with 3 crops: snapbeans (Phaseolus vulgaris L.), tomatoes (Lycopersicon esculentum L.), and red beets (Beta vulgaris L.). The lime treatments, check, calcitic lime, and dolomitic lime, were applied in 1979 and resulted in soil pH levels of 5.5, 6.9 and 6.7, respectively, at the time of planting. Banded fertilizer treatments were randomized in each lime plot. These were: check, NP, N, NPK, NPCa, and NPMg for snapbeans while with tomatoes and beets, K was added to the N, NPCa and NPMg treatments. Leaf samples from each plot were analyzed for 11 elements.

Growth responses of the 3 crops were related to the plant sensitivity to acid soils. When grown on soil with pH 5.5, snapbean vine weights and pod yields were not affected, tomato yields tended to be lower, and red beet yields were substantially reduced. Leaf Mn levels increased with the greater sensitivity to acid soils. Both calcitic and dolomitic limes had little effect on snapbean yields, moderate effects on tomato yields, and more than doubled yields of red beets. Lime types affected primarily leaf Ca and Mg. The NPK fertilizer treatment increased yields of tomatoes and red beets but increased only vine weights of snapbeans. Leaf Mn was increased substantially in the NPK treatment. When gypsum or Epsom salts was added, yields were not affected.

The sensitivity of red beets and to a lesser extent tomatoes could not be explained on the basis of manganese toxicity or poor uptake of calcium or magnesium. The results did suggest that poor phosphorus uptake could be a primary cause.     

Ionic equilibria,selectivity and diffusion of cations in soil as influenced by anion additions

Abstract

An experiment was carried under controlled conditions to investigate the influence of the anions, H₂PO₄ ^‐. and Cl on the ionic equilibria, selectivity and effective diffusion of Rb, K, Na, Ca, Mg in two Indiana soils.

Additon of anions to the soils increased the concentration of cations in soil solution. In both the soils receiving H₂PO₄ ^‐, lower cation concentrations were found in the soil solution than in those receiving Cl^‐ . Additon of H₂PO₄ ^‐and Cl^‐ reduced the ion selectivity coefficient, k, for various homovalent (Rb/K, Rb/Na, K/Na, Ca/Mg) and mono‐divalent ion pairs (Rb/Ca, Rb/Mg, K/Ca, K/Mg). In Zanesville soil treatments receiving H₂PO₄ ^‐ had lower k values for mono‐divalent cations than treatments receiving Cl^‐. However, no such conclusions could be drawn for Raub soil. Soils treated with H₂PO₄ ^‐ had higher k values for homovalent cations than Cl^‐ treated soils. The differences in the selectivity of adsorption in these two soils might be attributable to the differences in the type and nature of exchange materials and cation concentrations on the exchange phase.

Addition of H₂PO₄ ^‐ or Cl^‐ enhanced the magnitude of effective diffusion coefficient. (De) of all the cations under considerations. The magnitude of effective diffusion coefficient for cations was lower for H₂PO₄ ^‐ treated soils than Cl^‐ treated soils. Such a reduction in De is related to the reduction in cation concentration in soil solution thereby increasing the buffer capacity for the ions under consideration.     

Influence of nitrate and ammonium on critical nitrogen deficiency concentrations and mineral composition of Dupontia fisheri grown hydroponically in a controlled environment

Dupontia fisheri plants, derived from a clone, were propagated in plant growth chambers by the open‐pot nutrient solution technique, with vermiculite as the solid phase. The plants were illuminated continuously at 21, 500 lux (2,000 f.c.) by a combination of fluorescent and incandescent lamps. Air temperature was kept constant at 20°C. The plants, after transplanting to 20‐liter pots (closed‐pot system), were nourished by a modified half‐strength Hoagland solution, supplied with a one time addition of nitrogen at the rate of zero, 0.25, 0.5, 1.0, 2.0, 4.0 and 8.0 me/1 derived from (NH₄)₂SO₄, Ca(NO₃)₂ or NH₄NO₃. They were harvested 49 days after transplanting at a time when those in the three lowest treatments were distinctly deficient in nitrogen. Critical nitrate‐N values (the concentration at a 10% reduction in vegetative growth) were found to be identical, at 100 μg/g (dry basis), in the stem, blade‐1 and blade‐3 tissues, and those for total‐N at 0.901, 2.251, and 2.501, respectively.

Absence of nitrate in stem tissue indicated a nitrogen deficiency while the total‐N value indicated the degree of deficiency: the lower the value the greater the deficiency. Nitrogen also influenced the mineral composition of stem and blade tissues directly, mainly by ionic competition, and possibly indirectly, by decreasing dry matter content as the plants became less deficient in nitrogen. Transitions from nitrogen deficiency to sufficiency caused relatively large changes in the concentration of other nutrients in both stems and blades, but sometimes in opposite directions. For example, soluble‐P and total‐P in stems increased dramatically with increases in total‐N, but decreased greatly in the blade‐1 and blade‐3 tissues. Potassium, on the other hand, increased greatly in all tisues with increases in total‐N. These effects were much smaller for phosphorus with ammonium‐N as a nitrogen source than with nitrate, but for potassium there was no appreciable effect of nitrogen source in stems, a larger effect in blade‐1 and an erratic effect in blade‐3. Additionally, there were rather large decreases in manganese concentration with increases in nitrogen while effects on other nutrients were either small (Mg and Zn) or not significant (Ca, Fe, Cu and Na). All values were above critical concentrations.     

Tomato growth,nitrogen fraction and mineral composition in response to nitrate and ammonium foliar sprays 1

Tomato plants were grown in sand culture with NO₃ or NH₄ N at two levels of light. Foliar sprays at three levels of N as well as combinations of foliar and root feeding were used.

Shade increased NH₄ toxicity in plants sprayed with NH₄ but decreased the toxicity in plants receiving NH₄ through the roots. NH₄‐N greatly reduced growth and cation uptake when supplied through the roots but not with foliar application. Plants sprayed with NH₄ showed better growth, higher K, Ca, and Mg content and lower free NH₄ in shoot, compared to plants receiving NH₄ through the roots.

The overall free amino acid contents of shoots was higher for NH₄‐fed plants regardless of how the N was applied. Plants sprayed with NH₄ incorporated a greater amount of N into insoluble compounds compared with NO₃ nutrition. The N uptake per unit of leaf area was higher for plants grown under full sun light whereas N content was higher for plants grown under hade. N content in tissue increased with N concentration in foliar spray, although plants supplied with N through the roots had higher levels of free amino acids and total nitrogen.