Shoot Macronutrient Research Articles

Sewage sludge organic fertilizer as a promoter of initial growth of Euterpe edulis Mart., an endangered palm

Purpose The overharvesting of the endemic palm tree Euterpe edulis Mart. (Arecaceae) from the Brazilian Atlantic Forest hotspot and the destination given to the sludge produced from urban sewage treatment are both serious environmental issues caused by human activities. In order to find solutions or alternatives for both the issues, we aimed to investigate the effect of increasing rates of a sewage sludge organic fertilizer (SSOF), produced by composting sewage sludge and solid waste, on the initial growth of E. edulis. Methods We mixed sand with 0, 62.5, 125, and 250 kg·m−3 of SSOF in 8 L (21 cm height × 24 cm top diameter × 20.5 cm base diameter) pots and then planted a seedling of E. edulis in each pot. We assessed the seedlings’ height and stem diameter relative growth rate (RGR), biomass, root to shoot ratio, and shoot macronutrient (nitrogen, phosphorous, potassium, calcium, magnesium, and sulphur) concentrations in relation to fertilizer levels. We also evaluated the relation between plant height and diameter over time for each fertilization level. Results We found that height and stem diameter RGRs, biomass accumulation, and N and P shoot concentrations of E. edulis were positively related to SSOF levels between 120 and 250 kg·m−3 in the substrate. Conclusions Our study demonstrates that SSOF can be further used as an alternative to sewage sludge disposal and contribute to E. edulis cultivation, and, hence, its conservation.

Effects of Rhizobium inoculation and cropping systems on macronutrients uptake and partitioning in two legumes (Common bean and Lablab)

The study to investigate the effect of Rhizobium inoculation and cropping systems on the uptake of macronutrients in shoot, root and whole plant of Phaseolus vulgaris and Lablab purpureus was conducted at Selian Agricultural Research Institute (SARI) for two cropping seasons. A randomized complete block design was used in a 3-factorial arrangement with two levels of Rhizobium (with and without rhizobia), two legumes (P. vulgaris and L. purpureus) and five cropping systems (sole maize or sole legumes, 1 row maize to 1 row legumes (1:1) i.e. 0 m or 0.45 m of legume from maize row, 1 row maize to 2 rows of legumes (1:2) i.e. 0.1 m or 0.2 m of legumes from maize rows). The result showed that Rhizobium inoculation significantly (P£0.001) increased the uptake of N, P, K, Ca and Mg in the plant parts and whole plant. Similarly, cropping systems significantly (P£0.001) increased the uptake of N, K and Mg in shoots and whole plant of P. vulgaris and L. purpureus but decreased the P and Ca content in roots. Legumes significantly increased the uptake of the macronutrients in shoots and roots but more nutrients concentration in shoots than roots for both cropping seasons. There were significant (P£0.001) interaction between; Rhizobium x legumes x cropping systems on whole plant uptake of N in cropping season 1 and 2. Regardless of the type of interaction, inoculated legumes maximized the uptake of macronutrients in shoots, roots and whole plant.

Absorption of primary macronutrients and soybean growth at different compactation densities and moisture levels in a silt loam soil

ABSTRACT Soybean cultivation is increasing rapidly in the region of Alto Vale do Itajaí, State of Santa Catarina, where there is a predominance of silt soils. The objective of this work was to evaluate the content of primary macronutrients in shoots and shoot and root vegetative growth of soybean (Glicine max L. Merrill) grown in a silt-loam soil under different compactation densities and moisture levels. A randomized block design in a 4x4 factorial arrangement was used, with four compactation densities: 1.00; 1.20; 1.40 and 1.60 Mg m-3, and four soil moisture levels: 0.130; 0.160; 0.190 and 0.220 kg kg-1 and four replications. Each pot consisted of the overlapping of three 150-mm PVC rings, where soil was maintained in the higher and lower part of the pot with a density of 1.00 Mg m-3 and in the intermediate ring, the compactation densities were increased. Values of soil density higher than 120 Mg m-3 negatively affected N, P and K uptake by soybean plants, as well as the plant mass of the shoots and roots. The higher levels of soil moisture reduced the compaction effect and promoted better absorption of P and K.

Bio-inoculation of yerba mate seedlings (Ilex paraguariensis St. Hill.) with native plant growth-promoting rhizobacteria: a sustainable alternative to improve crop yield

In this study, the role of native plant growth-promoting rhizobacteria (PGPR) as bio-inoculants was assessed as an alternative to ameliorate Ilex paraguariensis St. Hill. growth in nursery comparing poorer (soil) versus richer (compost) substrates. Twelve rhizospheric strains isolated from yerba mate plantations were evaluated in vitro for their potential as PGPRs. Three isolates, identified as Kosakonia radicincitans YD4, Rhizobium pusense YP3, and Pseudomonas putida YP2, were selected on the basis of their N2 fixation activity, IAA-like compound and siderophore production, and phosphate solubilization. A highly significant positive effect of bio-inoculation with the native isolates was observed in 5-month-old seedlings cultivated in soil. The highest increase was observed in seedlings inoculated with K. radicincitans YD4 with an increase of 183 % in the dry shoot weight and a 30 % increase in shoot N content. In contrast, in compost, no increment in the dry weight was observed; however, an increase in content in some macronutrients in shoots was observed. Remarkably, when plant biomass was compared between soil and compost, seedlings inoculated with K. radicincitans YD4 in soil produced the highest yields, even though higher yields could be expected in compost due to the richness of this substrate. In conclusion, bio-inoculation of yerba mate seedlings with native PGPR increases the yield of this crop in nursery and could represent a promising sustainable strategy to improve yerba mate growth in low-fertility soils.

Desenvolvimento e estado nutricional da beterraba em função da omisão de nutrientes

Com o objetivo de avaliar o efeito da omissão de macronutrientes no desenvolvimento e no estado nutricional da beterraba, assim como descrever sintomas visuais de deficiência nutricional, um experimento foi conduzido em casa de vegetação da UNESP, Campus de Jaboticabal, SP. O delineamento experimental foi inteiramente casualizado, com sete tratamentos, que corresponderam à solução completa (macro e micronutrientes) e à omissão individual de N, P, K, Ca, Mg e S, com três repetições. Avaliou-se a altura das plantas, o número de folhas, a área foliar, a matéria seca da parte aérea, da raiz e planta inteira, os teores dos macronutrientes da parte aérea e raiz e descritos as desordens nutricionais. As omissões individuais de N, P, K e Ca foram as mais limitantes para o crescimento vegetativo da beterraba, reduzindo consideravelmente a altura, o número de folhas e as matérias secas de parte aérea, raiz e planta inteira. Foram observados sintomas de deficiência nutricional de cada elemento. Os teores dos macronutrientes na parte aérea do tratamento completo e com omissão dos nutrientes foram respectivamente: N = 32,9 - 13,8; P = 9,0 - 0,8; K = 126,0 - 15,1; Ca = 12,0 - 1,0; Mg = 10,1 - 0,7; S = 3,6 - 1,2 g kg-1.

EARLY FLOODING OF TWO CULTIVARS OF TROPICAL MAIZE. II. NUTRITIONAL RESPONSES

The level of oxygen in soils affects the bio-availability of nutrients as well as the ability of root systems to uptake and transport water and mineral nutrients. However, efforts addressing management practices to reduce yield losses after transient flooding have had limited success. Since after-drainage nitrogen (N) fertilization has been proposed to mitigate crop damage, a closer examination of plant nutrient acquisition during this period is required. In this work, we compare the short-term changes in the tissue levels of macronutrients [N, phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)] in two varieties of tropical maize differing in tolerance to poor soil drainage, after a six day period under water saturated conditions, early during the vegetative growth. Two Venezuelan varieties, one labeled as tolerant and the other as susceptible to limited soil drainage, were planted in 10-kg pots and flooded at the seventh-leaf-tip (V4) stage. Treatments included a post-drainage N fertilization. Plant responses were compared to corresponding non-flooded plants. Flooding the soil reduced concentrations of macronutrients in shoots, compared to well aerated plants. Calcium and Mg levels were also reduced in roots, whereas K concentrations increased. After a post-drainage recovery period, nutrient concentration in shoots of flooded plants were above those of non-flooded ones, due to higher uptake rates. The only exception was P, where reduced acquisition appears to limit plant recovery. A post-flood N-urea fertilization increased the concentrations of N, Ca and Mg in shoots, but failed to increase shoot growth after 15 days. Differences in the pattern of Ca accumulation suggested a possible role of Ca nutrition in the tolerance of maize to flooding.

Seasonal dynamics of production, and nutrient accumulation and cycling by Phragmites asutralis (Cav.) Trin. ex Stuedel in a nutrient-enriched swamp in Inland Australia. II. Individual Shoots

The seasonal dynamics of the growth of shoots of Pragmites australis, and the partitioning of dry matter and 12 mineral nutrients between shoot organs, were studied in a stand in a nutrient-enriched swamp in inland Australia. The stem accumulated over 75% of the total-shoot dry matter, the inflorescence less than 5%. About 26% of the shoot dry matter was redistributed to below-ground organs during senescence. K and N were the most concentrated macronutrients in shoots, followed by Cl>> Ca > S > P > Mg > Na. Micronutrient concentrations were in the order Mn > Fe >> Zn > Cu. Concentrations of most nutrients and total amino compounds were higher in leaves than stems. Concentrations of N, P and K were highest in young shoots and decreased throughout the season, whereas concentrations of Ca, Cl, Fe, Mn and Na increased during the life of the shoot. There were gradients of concentration of some nutrients in the stem and leaves from the base to the top of the shoot. The top of the shoot had the highest concentrations of nutrients. Ca and Mn accumulated mainly in the large leaves from the middle of the shoot. The stem contained the major proportion of the quantity of most nutrients in living shoots; however, leaves had over 55% of the total shoot content of N, Ca and Mn. The inflorescence usually had less than 10% of the quantity of a nutrient in the shoot, but had over 20% of the N and 32% of the P in the shoot. N, P and K were redistributed from senescing shoots to below-ground organs with over 60% efficiency, and S, Mg, Zn and Cu with between 17 and 38% efficiency. There was negligible redistribution of Ca, C1, Na, Fe or Mn from either leaves or stems. Nutrients were redistributed to a greater extent from leaves than from stems. There were leaching losses of some nutrients from exposed senescing shoots, especially with K, C1 and Na. Nutrients were leached more readily from leaves than from stems. Leaching losses of N were low (c. 5%). Shoots from part of the reed-bed burnt the previous winter were smaller, had fewer leaves, and had lower concentrations of most nutrients than those from the unburnt part of the reed-bed.