Dry matter production in relation to root plastic development, oxygen transport, and water uptake of rice under transient soil moisture stresses

FITOMASSA E ACUMULO DE MACRONUTRIENTES EM CANA-DE-AÇÚCAR SOB COMPACTAÇÃO E UMIDADE DO SOLO OTAVIO BAGIOTTO ROSSATO1; JORGE MARTINELLI MARTELLO2; CARLOS ALEXANDRE COSTA CRUSCIOL3 1Professor do Instituto Federal Catarinense, CEP 89700-000, Concórdia, SC, Brasil.E-mail: [email protected] em Agronomia – Energia na Agricultura, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista (UNESP), CEP 18610-307, 237, Botucatu, SP, Brasil.E-mail: [email protected] do Departamento de Produção e Melhoramento Vegetal, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista (UNESP), CEP 18610-307, 237, Botucatu, SP, Brasil. E-mail: [email protected] 1 RESUMO O experimento foi realizado em tubos de PVC, em casa de vegetação, usando um delineamento de blocos ao acaso, com quatro repetições, com tratamentos arranjados em esquema fatorial (4x3x2), equivalente a quatro variedades, 3 níveis de compactação do solo na camada de 0,20 a 0,30 m (1,35; 1,45 e 1,55 Mg m-3) e 2 teores de água no solo (70% e 90% da capacidade de campo). Aos 72 dias após emergência da plantas foram avaliadas a massa seca de raízes e parte aérea e os teores de N, P, K, Ca, Mg, S acumulados na parte aérea da cana-de-açúcar. O maior nível de umidade no solo propiciou aumento na produção de matéria seca de raiz e da parte aérea além de maior acúmulo de N, P, K, Ca, Mg e S na parte aérea da cana-de-açúcar, independentemente da variedade e nível de compactação. Além disso, na variedade RB72454 obteve-se maior produção de matéria seca da parte aérea e maior acúmulo de N, P, K, Ca, Mg e S que as demais variedades quando sob maior disponibilidade de água no solo. O maior nível de compactação do solo promoveu redução na produção de matéria seca da parte aérea e no acúmulo de N, P, K, Ca e Mg na parte aérea da cana-de-açúcar, independentemente da variedade utilizada. Em solos com menor disponibilidade de água (70%CC), o maior nível de compactação do solo (1,55 Mg m-3) promoveu redução na produção de biomassa da parte aérea e no acúmulo de N, P, K, Ca e Mg. Palavras-Chaves: Saccharum spp, teor de água no solo, densidade, matéria seca, raiz, nutrientes, parte aérea. ROSSATO, O. B.; MARTELLO, J. M.; CRUSCIOL, C. A. C.DRY MATTER PRODUCTION AND MACRONUTRIENT ACCUMULATION IN SUGARCANE GROWN UNDER LEVELS OF COMPACTION AND SOIL MOISTURE 2 ABSTRACT The experiment was conducted in PVC tubes, in a greenhouse, using a randomized block design with four replications, in a factorial arrangement (4x3x2) equivalent to four varieties, three levels of soil compaction in the layer 0.20 to 0.30 m (1.35, 1.45 and 1.55 Mg m-3) and two soil moisture contents (70% and 90% of field capacity). 72 days after the plants emergence the dry mass of roots and shoots and N, P, K, Ca, Mg, S contents accumulated in shoots of sugarcane were assessed. The results show that the higher moisture level in the soil led to increases in dry matter production of shoots and roots besides higher accumulation of N, P, K, Ca, Mg and S in sugarcane shoots regardless of the variety and level of compaction. In addition, variety RB72454 provided greater shoots with dry matter and higher accumulation of N, P, K, Ca, Mg and S on shoots than in other varieties under greater availability of water in the soil. The highest level of soil compaction promoted reduction in shoot dry matter production and accumulation of N, P, K, Ca and Mg on shoots of sugarcane regardless of the variety used. On soils with lower water availability (70% of field capacity), the highest level of soil compaction (1.55 Mg m-3) promoted a reduction on shoot biomass production and accumulation of N, P, K, Ca and Mg. Keywords: Saccharum spp, soil water content, density, dry matter, root, nutrients, shoot.

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Competition Between Wheat and Wild Buckwheat

Weed Science ◽

10.1017/s0043174500046919 ◽

1968 ◽

Vol 16 (2) ◽

pp. 204-208 ◽

Cited By ~ 12

Author(s):

L. J. Fabricius ◽

John D. Nalewaja

Keyword(s):

Soil Moisture ◽

Soil Fertility ◽

Dry Matter ◽

Phosphorus Uptake ◽

Dry Matter Production ◽

Water Usage ◽

Nitrogen And Phosphorus ◽

Wild Buckwheat ◽

Matter Production ◽

Nitrogen And Phosphorus Uptake

An experiment was conducted comparing wheat (Triticum aestivum L., var. Pembina) and wild buckwheat (Polygonum convolvulus L.) grown alone in pots, in full competition, and in root competition at three levels each of soil fertility and soil moisture, and harvested at three dates.Wheat was a better competitor than wild buckwheat when considering dry matter production. With each succeeding harvest, the dry matter production and the total nitrogen and phosphorus uptake increased more for plants grown alone than in competition. Competition caused a reduction in the nitrogen and phosphorus content of wheat and wild buckwheat at the first harvest, while reductions in dry matter did not occur until the second harvest. Wheat increased in dry matter and nitrogen more than wild buckwheat with each higher level of soil moisture when grown alone but not when in competition. When grown alone or in competition, wheat increased linearly in dry matter production with increases in fertility while wild buckwheat produced maximum dry matter with medium fertility. The total nitrogen increased in wheat and wild buckwheat with each higher level of fertility, while total phosphorus increased only in wheat.Wild buckwheat used less water than wheat to produce a gram of dry matter and per milligram of phosphorus uptake when grown alone, while the plants in competition were intermediate in water usage to plants grown alone. Wild buckwheat and wheat used similar amounts of water per unit of nitrogen uptake when grown alone and increased their water usage when grown in competition. Water efficiency for nitrogen and phosphorus uptake and dry matter production usually decreased with plant maturity and higher soil moisture, and increased with higher soil fertility.

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