Amonização de superfosfato simples

Ordinary superphosphate run through 20 - 40 - 60 - 100 and plus mesh sieves were treated with 3 per cent (weight basis) of anhydrous ammonia in special aparattus. This amount reacting with normal superphosphate caused reversion in water soluble phosphate. The rate of ammoniation varied from 2,7 to 3,8% per unit of P2O5 considering the fraction before the treatment. The reversion range was from 44,6 to 57,9% of water soluble phosphate. The rate of correlation between solubility and ammonia dosis was -0,96 and the linear regression obtained was Y = 24,344-4,732x.Superfosfato simples separado em peneiras 20-40-60-100 e mais de 100 "mesh" foi tratado com 3% em peso de amônia anidra para avaliar a reversão do fosfato em presença de "amônia livre"

Estudos sôbre a nutrição mineral do feijoeiro (Phaseolus vulgaris L., var. roxinho)

6.1. The uptake of macronutrients by bean plants was studied under field conditions. It was shownthat higher production of dry matter was obtained when the crop was 56 days old. Total amounts absorved were, in kg/ha: N-101, P-9, K-93, Ca-54, Mg-18 and S-25. 6.2. When grgown in nutrient solution symptoms of deficiency were observed tor all nutrients under study. Anatomical lesions within the leaf tissue were also observed, the chloroplasts being particularly affected. The following leaf levels of elements in the dry leaves characterize conditions of deficiency: N-1.54%, P-0.13%, K-0,93%, Ca-0.42%, Mg-0.48%, S-0.70%.No presente trabalho foi estudada a marcha de absorção de macronutrientes pelo feijoeiro (Phaseolus vulgaris L., var. roxinho) em condições de campo. Verificou-se que a produção mais alta de matéria sêca ocorreu quando as plantas tinham 56 dias de idade, o que corresponde aproximadamente a dois terços do período necessário para completar o ciclo. As quantidades totais de macronutrientes absorvida em kg/ha foram: N-101, P-9, K-93, Ca-54, Mg-18 e S-25. Em outro experimento foram obtidos, cultivando-se as plantas em solução nutritiva, sintomas típicos de carência dos macronutrientes estudados. Cortes anatômicos das folhas mostraram que a omissão dos elementos do substrato causava lesões nos tecidos, sendo os cloroplastos as organelas particularmente afetadas. Os seguintes níveis foliares de elementos caracterizam deficiência dos mesmos nas condições experimentais: N-1,54%, P-0,13%, K-0,93%, Ca-0,42%, Mg-0,48%, S-0,70%

Nutrient extraction and exportation by common bean cultivars under different fertilization levels: I - macronutrients

The use of cultivars with a higher yield potential and the adoption of new technology have achieved high grain yields in common bean, which probably changed the demand for nutrients in this crop. However, there is almost no information about the periods of the cycle in which nutrients are most demanded at which quantities by the main cultivars. The objective of this study was to evaluate the macronutrient extraction and exportation by the common bean cultivars Pérola and IAC Alvorada, under different levels of NPK fertilization, on a dystroferric Red Nitosol, in Botucatu, São Paulo State, Brazil. The experiment was arranged in a randomized complete block (split plot) design with four replications. The plots consisted of six treatments based on a 2 x 3 factorial model, represented by two cultivars and three NPK levels (PD0 - 'Pérola' without fertilization, PD1 - 'Pérola' with 50 % of recommended fertilization, PD2 - 'Pérola' with 100 % of recommended fertilization, AD0 - 'IAC Alvorada' without fertilization, AD1 - 'IAC Alvorada' with 50 % of recommended fertilization, and AD2 - 'IAC Alvorada' with 100 % of recommended fertilization) and subplots sampled seven times during the cycle. At higher levels of NPK fertilization, the grain yield and macronutrient extraction and exportation of both cultivars were higher, but without statistical differences. Macronutrient absorption was higher in the treatments with 100 % of recommended NPK fertilization (average amounts per hectare: 140 kg N, 16.5 kg P, 120 kg K, 69 kg Ca, 17.9 kg Mg, and 16.3 kg S). Regardless of the treatment, the demand for N, P, K, Ca, and Mg was highest from 45 to 55 days after emergence (DAE), i.e., in the R7 stage (pod formation), while the highest S absorption rates were concentrated between 55 and 65 DAE. More than 70 % of P, between 58 and 69 % of N, 40 and 52 % of S, 40 and 48 % of K, and 35 and 45 % of Mg absorbed during the cycle was exported with grains, whereas less than 15 % of Ca was exported.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Department of Crop Science College of Agricultural Sciences São Paulo State University - FCA/UNESP, P.O. Box 37, CEP 18610-307 Botucatu SPFCA/UNESPDepartment of Crop Science College of Agricultural Sciences São Paulo State University - FCA/UNESP, P.O. Box 37, CEP 18610-307 Botucatu SPFCA/UNESPFAPESP: 10/18602-

Mineral nutrition of vegetable crops: XXV - Mineral nutrition of new zealand spinach plant (Tetragonia expansa Murr.)

The present work was carried out in order to study: a - the effect of omission and presence of the macronutrients and boron on the growth of the plants; b - deficiency symptoms of macronutrients, as well of boron; c - the effect of the deficiency of each nutrient on the chemical composition of the plants. Young spinach plants were grown in pots containing pure quartz sand. Several times a day the plants were irrigated by percolation with nutrient solutions. The treatments were: complete solution and deficient solution, in which each one of the macronutrients was omitted as well boron. Soon as the malnutrition symptoms appered, the plants were harvested and analysed chemically. - symptoms of malnutrition are easily observed for N, K, Ca and B. - symptoms of malnutrition for P, S and Mg are not easily identified. - the nutrient content, in dry matter, in deficient leaves and healthy leaves is:O trabalho teve como objetivo estudar alguns aspectos da nutrição mineral do espinafre (Tetragonia expansa Murr.) no que concerne: 1 - Efeitos da omissão dos macronutrientes e do boro, na obtenção de um quadro sintomatológico; 2 - Efeitos das carências na produção de matéria seca e composição química da planta. Mudas com trinta dias de idade foram transplantadas para soluções nutritivas carentes nos macronutrientes e/ou em boro. A coleta das plantas foi realizada quando os sintomas de deficiência se tornaram evidentes. No material seco procedeu-se a análise química. Os dados mostram que: 1 - os sintomas visuais de deficiência de N, K, Ca e B apresentam-se bem definidos; sendo que os de P, Mg e S são de difícil caracterização ; 2 - os teores dos nutrientes em plantas sadias e deficientes são

Concentração e acumulação de nitrogénio, fósforo e potássio pelo feijoeiro cultivado sob diferentes níveis de irrigação Nitrogen, phosphorus and potassium concentration and accumulation by black beans under several irrigation levels

O experimento foi conduzido com o objetivo de determinar a concentração e acumulação de N, P e K no feijoeiro (cv. BR Ipagro 1 "macanudo") cultivado sob diferentes níveis de irrigação: Sem irrigação (SI); irrigação ao ser atingida a tensão matricial de 80kPa (I-80kPa) e; a 40 kPa (I-40kPa). Os resultados obtidos no florescimento indicam que a concentração de N (3,72%) não variou em relação aos níveis de irrigação utilizados. Para o P, diferiu entre o SI (0,23%) e os irrigados (0,30%). Para o K, diferiu entre o SI (0,73%) e o l-40kPa (1,16%). Na maturação fisiológica, a concentração de N nos grãos variou e apresentou média de 3,47%. Entretanto, para P (0,54%) e K (0,89%) não variou. As quantidades totais de N, P e K acumuladas diferiram entre o tratamento SI e os tratamentos irrigados e apresentaram médias de 62,4 e I23,8kg de N/ha, 8 e 18,8kg de P/ha e 23,7 e 50,7kg de K/ha, respectivamente, para SI e irrigados.<br>This study was carried out with the objective to determine NPK concentration and accumulation of black beans (Phaseolus vulgaris L., BR Ipagro 1 "macanudo" varie ty) cultivated under different sprinkling irrigation levels. The three irrigation levels were: without irrigation (Wl), irrigation when matric potential reached 80kPa (I-80kPa) and 40kPa (I-40kPa). The results of the flowering sampling indicated that the N concentration (3.72%) was not affected by irrigation levels. Leaf concentration of P in the leaves were different between WI (0.23%) and the irrigated treatments (0.30%). In the maturity stage the N grains concentration changed with irrigation and presented average values of 3.47%. However. P (0.54%) and K (0.89%) grains concentrations were similar. The whole amount of NPK accumulated was different for WI and irrigated treatments. The average values of 62.4 and 123.8kg of N/ha, 8 and 18.8kg of P/ha and 23.7 and 50.7kg of K/ha, were observed for WI and irrigated treatments, respectively