SARAIVA, J.O. C.; SARAIVA, José Osmar Coelho.
Resumo:
The main purpose of this present work was the
improvement of a research study about furrow irrigation
method i n Vale do Açu-RN, with the objective to achieve
basic data to efficient lanagement of the irrigation.
Fieldworks were developed on average texture
latosols i n Production and Experimentation Physical Base, of
-the Empresa de Pesquisa Agropecuária do Rio Grande do Norte-
EMPARN, i n Ipanguaçú-RN.
Fieldtests were conduted i n 100 m lenght furrows
with average of 0,29 percent. Advance's equations were
established based on f l o w o f 1,52 l/s obtáined by formula
qmax= S , where and equal to 0,613 and - 0,733,
respctively. For this flow, furrows showed a moderated
erosion. Besides, they were realized for flows of 1,45 and
1,70 l / s . For the first flow, furrows didh't show any
erosion along of themselves, whereas for the second it was
well evident. Advance's equations and acumulated water
intake, determined with a flow of 1,45 l / s , were L= 10,62
T0,86 D= 4,78 T°'5 7(mm), o respectively.
The moestening strip reached by lateral water intake
with the action of a furrow. obtáined an average width of
76 cm, after 70 minutes of irrigation .
The method"s survery was done odedying the
metodology suggested by Bernado (1982) , for 50, 75, 100 and
125 m furrows lenght; valnes of R- varying from 1 up t o 4 and
flow reduction from 1,45 to 1,0 l/s ' and 0,75 l / s,
respctively.
The results analysis showed that the r e a l nomerosive
maximun flow f o r a slope of 0,29 percent was 1,45 l / s ; the
most efficient flow reduction•was from 1,45 to 1,0 l / s to
whatever value of R; furrows of 100 and 125 m lenght were
recommended with a médium watêr application efficiency of
75%.
