scholarly journals Alternative sugarcane production for conservation of sandy soils: sugarcane straw, intercropping and nitrogen

2020 ◽  
Vol 44 ◽  
Author(s):  
Leandro Flávio Carneiro ◽  
Ricardo Augusto de Oliveira ◽  
Heroldo Weber ◽  
Edelclaiton Daros ◽  
Guilherme Souza Berton ◽  
...  

ABSTRACT The expansion of sugarcane cultivation in the Center-South region of Brazil has led to the use of, mainly, areas with low-yielding sandy soils. In this context, the objectives of this study were to evaluate the maintenance of the sugarcane straw, Brachiaria grass intercropping in sugarcane fields and nitrogen fertilization and on sandy soils in the state of Paraná. The field experiment was installed in the Paranavaí-PR city, at a unit of the Interuniversity Network for the Development of the Sugarcane Sector (RIDESA). The soil was classified as Latossolo Vermelho-amarelo distrófico. The treatments in the plant cane stage, consisting of four nitrogen rates (0, 50, 100 and 150 kg ha-1) and monoculture or Brachiaria grass intercropping in sugarcane fields were arranged in a 4x2 factorial design. At plant cane harvest, the effect of unremoved straw was included as a new factor to be evaluated in the ratoon crops. The treatments in the ratoon crops were arranged in a 4x2x2 factorial design, consisting of four nitrogen rates (0, 50, 100 and 150 kg ha-1), monoculture or Brachiaria grass intercropping in sugarcane fields and the presence or removal sugarcane straw. The sugarcane straw on soil surface can increase the agronomic development of sugarcane and, the other hands, Brachiaria grass intercropping in sugarcane fields can reduce. Sugarcane was responsive to N rates and, in the highest rates, compensated the sugarcane straw absence and reduced Brachiaria grass intercropping competition.

2013 ◽  
Vol 31 (1) ◽  
pp. 165-174 ◽  
Author(s):  
N.M Correia ◽  
E.H Camilo ◽  
E.A Santos

The aim of this study was to assess the capacity of sulfentrazone applied in pre-emergence in controlling Ipomoea hederifolia and Ipomoea quamoclit as a function of the time interval between herbicide application and the occurrence of rain, and the presence of sugarcane straw on the soil surface. Two greenhouse experiments and one field experiment were conducted. For the greenhouse experiments, the study included three doses of sulfentrazone applied by spraying 0, 0.6, and 0.9 kg ha-1, two amounts of straw on the soil (0 and 10 t ha-1), and five time intervals between the application of herbicide and rain simulation (0, 20, 40, 60, and 90 days). In the field experiment, five herbicide treatments (sulfentrazone at 0.6 and 0.9 kg ha-1, sulfentrazone + hexazinone at 0.6 + 0.25 kg ha-1, amicarbazone at 1.4 kg ha-1, and imazapic at 0.147 kg ha-1) and two controls with no herbicide were studied. Management conditions with or without sugarcane straw on the soil were also assessed. From the greenhouse experiments, sulfentrazone application at 0.6 kg ha-1 was found to provide for the efficient control of I. hederifolia and I. quamoclit in a dry environment, with up to 90 days between herbicide application and rain simulation. After herbicide application, 20 mm of simulated rain was enough to leach sulfentrazone from the straw to the soil, as the biological effects observed in I. hederifolia and I. quamoclit remained unaffected. Under field conditions, either with or without sugarcane straw left on the soil, sulfentrazone alone (0.6 or 0.9 kg ha-1) or sulfentrazone combined with hexazinone (0.6 + 0.25 kg ha-1) was effective in the control of I. hederifolia and I. quamoclit, exhibiting similar or better control than amicarbazone (1.4 kg ha-1) and imazapic (0.147 kg ha-1).


2020 ◽  
Vol 46 (4) ◽  
pp. 345-347
Author(s):  
Erlei Melo Reis ◽  
Mateus Zanatta ◽  
Andrea Camargo Reis

ABSTRACT The evolution of the reduction in Asian soybean rust (caused by Phakopsora pachyrhizi) control by site-specific fungicides has been reported season after season. In a field experiment, the effect of prothioconazole solo and added to multisite mancozeb was evaluated for rust control. Treatments were evaluated in a factorial design of four prothioconazole doses and three mancozeb doses. In a set of treatments, three applications were performed in one soybean cycle and four applications in another one. The first applications were performed at GS V8, 11 days before rust detection, with 2.56% leaflet incidence, while the other applications were at 12 to 14-day interval. Rust severity was quantified, control was calculated in relation to the unsprayed treatment, and soybean grain yield was estimated as kg/ha. Fifty-one to 61% control was obtained with three sprayings and 68% to 70% control with four sprayings of prothioconazole alone. Over 80% control was obtained with at least 0.3 L/ha prothioconazole + 2.0 kg/ha mancozeb, corresponding to 75 g a.i./ha prothioconazole + 1500 g a.i./ha mancozeb. Reduction in P. pachyrhizi control by the use of the site-specific fungicide alone was confirmed, while the addition of mancozeb can recover the efficacy of the site-specific fungicide.


AGROFOR ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Ivan VELINOV ◽  
Zhivko TODOROV ◽  
Svetla KOSTADINOVA

The uptake and expense of nitrogen, phosphorus and potassium in grain sorghum was studied in a field experiment during the period 2017-2018. Hybrid EC Alize was grown under non-irrigated conditions. The applied nitrogen fertilization was in rates 0, 60, 120, 180, 240 and 300 kg N.ha-1. It was established that application of N240 and N300 let to high average uptake of nitrogen (212.0 kg N.ha-1) and phosphorus (125.2 kg P2O5.ha-1) in maturity. The higher removal of 159.9 kg K2O.ha-1 on average was observed at N180 rate. The expense of nitrogen for production of 1 t of grain increased in parallel with the nitrogen fertilization. The highest nitrogen expense of 39.7 - 45.3 kg N.t-1 grain was established when sorghum received 300 kg N.ha-1 and it exceeded the control by 38.8 in 2017 and by 53.6% in 2018. Sorghum plants used 15.5 - 16.6 kg P2O5 an average to form 1 t of grain and nitrogen fertilization in rates N60-N300 slightly affected the phosphorus expense. Nitrogen fertilization proven increased the expense of potassium for production of 1 t of grain compared to N0 control plants. The increase was by 8.3 -20.0% in 2017 and by 8.0 - 34.0% in 2018. Sorghum plants expensed 23.2 - 24.2 kg K2O on average to form 1 t of grain at nitrogen rates N180-N300. The strong positive correlation was established between nitrogen fertilization with N uptake (0.966**) and N expense (0.997**) and K uptake (0.820*) and K expense (0.870*).


1987 ◽  
Vol 27 (1) ◽  
pp. 87 ◽  
Author(s):  
MDA Bolland

In 2 experiments on sandy soil near Esperance, W. A., superphosphate and Duchess (Queensland) apatite rock phosphate were either left on the soil surface after application (topdressed) or incorporated into the top 10 cm of the soil with a rotary hoe (incorporated). One experiment was on Fleming gravelly sand which had a greater capacity to adsorb phosphorus than did the deep yellow sand (Gibson sand) used in the other experiment. Dry matter or seed yield of subterranean clover and phosphorus content of dry herbage or seed were used as indicators of the effectiveness of the phosphorus treatments. Compared with topdressed superphosphate, incorporation of superphosphate did not greatly influence its effectiveness on the Gibson soil, but reduced its effectiveness by about 20% on the Fleming soil. Relative to topdressed rock phosphate, incorporation of rock phosphate almost doubled its effectiveness on the Fleming soil, and improved its effectiveness by about 1.5 times on the Gibson soil. Superphosphate was the more effective fertiliser. Relative to topdressed superphosphate, the effectiveness of topdressed and incorporated Duchess rock phosphate, respectively, was about 15 and 30% on the Fleming soil, and about 25 and 40% on the Gibson soil. There was no evidence of any leaching of phosphorus from Duchess rock phosphate from the 0-10 cm layer of either soil, nor of superphosphate on the Fleming soil. However, on the Gibson soil, there was some leaching of superphosphate to below 10cm, but not below 20 cm.


Revista CERES ◽  
2016 ◽  
Vol 63 (6) ◽  
pp. 887-892
Author(s):  
Sanzio Mollica Vidigal ◽  
Iza Paula de Carvalho Lopes ◽  
Mário Puiatti ◽  
Maria Aparecida Nogueira Sediyama ◽  
Marcelo Resende de Freitas Ribeiro

ABSTRACT Response of taro to amount of nitrogen applied and time of application has been the subject of discussion. The objective of this study was to evaluate the effect of nitrogen topdressing on taro yield. Two experiments were conducted in Oratórios - MG from September 2010 to July 2011 (Year 1) and from September 2011 to July 2012 (Year 2). Both experiments were arranged in a randomized block design, with four replications. The treatments consisted of five N rates (0; 40; 60; 80 and 160 kg ha-1) applied as topdressing at urea form. The corms of Japanese clone (BGH 5925) were planted in the 0.90 x 0.30 m spacing. In the two experimental years, yield increased in almost all corm classes with the increase in N rates. The estimated maximum yields of marketable corms were 22.23 Mg ha-1 in Year 1 and 9.81 Mg ha-1 in Year 2, with 109 and 118 kg ha-1 of N, respectively. The total number of corms per plant was similar in both years (16.45 corms/plant in Year 1 and 17.76 corms/plant in Year 2). Unmarketable corms represented 35.32 and 46.51% of the total per plant, in Year 1 and Year 2, respectively, indicating less corm growth in Year 2. The curve of taro response to topdressing N rates was similar in the two years and, the estimates were influenced by the difference in rainfall between the years. With the management of nitrogen fertilization, the maximum yield of marketable taro corms was achieved with N rates varying from 109 to 118 kg ha-1.


2016 ◽  
Vol 15 (3) ◽  
pp. 418
Author(s):  
SHEILA CAIONI ◽  
EDSON LAZARINI ◽  
TIAGO DE LISBOA PARENTE ◽  
RAUL SOBRINHO PIVETTA ◽  
LUIZ GUSTAVO MORETTI DE SOUZA

RESUMO – A maior parte do nitrogênio (N) é absorvida pela cultura do milho na forma de nitrato (NO3 -), que é reduzido na planta pela ação da enzima nitrato redutase, a qual tem o molibdênio (Mo) como um dos principais constituintes. O objetivo deste trabalho foi avaliar doses de N em conjunto com Mo na cultura do milho irrigado, cultivado em sistema plantio direto. O experimento foi desenvolvido no município de Selvíria, MS. O delineamento utilizado foi o de blocos casualizados em parcelas subdivididas com quatro doses de N (0, 90, 135 e 180 kg ha-1) e cinco doses de Mo (0, 10, 20, 30 e 40 g ha-1), com quatro repetições. Foram avaliados atributos morfológicos e produtivos da cultura. A maior produtividade de milho foi obtida com 180 kg ha-1 de N e com 25,6 g ha-1 de Mo.Palavras-chave: adubação nitrogenada, micronutriente, plantio direto, Zea mays L.NITROGEN AND MOLYBDENUM FOR IRRIGATED MAIZE IN THE BRAZILIAN SAVANNAH WITH LOW ALTITUDEABSTRACT – Most of nitrogen (N) is absorbed by maize as nitrate (NO3 -), that is reduced in the plant by the action of the nitrate reductase enzyme, which has molybdenum (Mo) as a major component. The objective of this study was to test N rates together with Mo for irrigated corn grown in no-tillage system. The experiment was conducted at the Selviria county, Mato Grosso do Sul State. The design was a randomized complete block with split plots, with four nitrogen rates (0, 90, 135 and 180 kg ha-1) and five doses of Mo (0, 10, 20, 30 and 40 g ha-1), with four replications. Morphological and productive attributes of corn crop were evaluated. The highest yield was obtained with 180 kg ha-1 N and 25.6 g ha-1 Mo.Keywords – nitrogen fertilization, micronutrient, no-tillage, Zea mays L.


2011 ◽  
Vol 29 (3) ◽  
pp. 398-403 ◽  
Author(s):  
Aurélio P Barros Júnior ◽  
Arthur B Cecílio Filho ◽  
Bráulio Luciano A Rezende ◽  
Diego RQ Pôrto ◽  
Renato de M Prado

The work was carried out at UNESP, Jaboticabal, São Paulo State, Brazil, from September to December 2006, to evaluate the effect of nitrogen fertilization on intercropping of lettuce and rocket. The experiment was conducted in a randomized complete block design, with four replications, treatments being arranged in a 4 x 4 + 2 factorial design. The treatments were the result of a combination of four N rates for lettuce (0, 65, 130 and 195 kg ha-1) and four N rates for rocket (0, 65, 130 and 195 kg ha-1), plus two additional treatments, which corresponded to lettuce and rocket under single cropping. Veronica (lettuce) and Folha Larga (rocket) were the cultivars used. An increase in the N rate for both cultures, under intercropping system, caused fresh matter gains and higher yields for lettuce and rocket, maximizing the land equivalent ratio (1.84) at 127 kg ha-1 of N for lettuce and 195 kg ha-1 of N for rocket.


2018 ◽  
Vol 39 (6) ◽  
pp. 2501
Author(s):  
Stephanie Vicente de Bessa ◽  
Alessandro José Marques Santos ◽  
Clarice Backes ◽  
Lucas Matheus Rodrigues ◽  
Arthur Gabriel Teodoro ◽  
...  

The objective of this study was to evaluate the effect of nitrogen topdressing rates applied to an intercrop of maize (M) with paiaguás grass (G) and pigeonpea (P) on silage production and on the pasture development in the offseason. Treatments consisted of two simultaneous intercropping systems (M + G; and M + G + P) and four N topdressing rates (0, 80, 160, and 240 kg ha?1). The introduction of pigeonpea into the system and the increasing N rates provided gains in yield and silage quality. Pigeonpea responded to nitrogen fertilization by having good regrowth and good dry matter yields in the intercrop. For silage making, the N rates of 240 kg ha?1 N for M+G and 120 kg ha?1 for M+G+P can be recommended. Nitrogen rates promote an increase in the dry matter yield of the grass and of pigeonpea, resulting in improvements in the pasture during the offseason.


Perception ◽  
2021 ◽  
pp. 030100662110140
Author(s):  
Xingchen Zhou ◽  
A. M. Burton ◽  
Rob Jenkins

One of the best-known phenomena in face recognition is the other-race effect, the observation that own-race faces are better remembered than other-race faces. However, previous studies have not put the magnitude of other-race effect in the context of other influences on face recognition. Here, we compared the effects of (a) a race manipulation (own-race/other-race face) and (b) a familiarity manipulation (familiar/unfamiliar face) in a 2 × 2 factorial design. We found that the familiarity effect was several times larger than the race effect in all performance measures. However, participants expected race to have a larger effect on others than it actually did. Face recognition accuracy depends much more on whether you know the person’s face than whether you share the same race.


1999 ◽  
Vol 79 (2) ◽  
pp. 303-310 ◽  
Author(s):  
F. L. Wang ◽  
A. K. Alva

Leaching of water soluble soil carbon plays an important role in downward transport of soil nutrients and pollutants and may be influenced by soil and management factors. We examined the leaching of water soluble carbon from two sandy soils under nitrogen fertilization by adapting an intermittent leaching-incubation technique using packed soil columns (94 × 10 cm). After 30 d, cumulative amounts of water-soluble organic carbon (SOC) leached from the Candler and Wabasso sand for various treatments in mg C column−1 were: 77 and 302 (NH4NO3), 64 and 265 (control), and 45 and 239 (isobutylidene diurea, IBDU), respectively. The IBDU and NH4NO3 treatments increased the leaching of water-soluble inorganic carbon (SIC), which ranged from 2 to 38 mg C column−1 over 30 d. At the end of eight cycles of leaching/incubation, the total carbon content increased at depth (control and NH4NO3 treatment) in the Candler sand, but decreased in the Wabasso sand. In the first leaching event, the average rate of SOC leaching from the Wabasso sand was 26 mg C column−1 d−1 which dropped rapidly to about 5 mg C column−1 d−1 towards the end of the experiment. The rate of SOC leaching from the Candler sand was much lower (<8 mg C column−1 d−1) than the rate of SOC leaching from the Wabasso sand. Compared with the unamended treatments, application of NH4NO3 increased and IBDU decreased the leaching of SOC in both soils. These effects of N application were considerable during the initial two to three leaching events only. Our results suggest that the initial rainfalls that follow a dry period may be critical for transporting SOC from the upper layer of these sandy soils. Key words: C leaching, sandy soil, intermittent leaching condition, isobutylidene


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