Water productivity and nitrogen use efficiency of irrigated paddy under transplanting, wet seeding and dry seeding | |
| Author | Rajaratnam, Thabonithy |
| Call Number | AIT Thesis no. IR-93-06 |
| Subject(s) | Water in agriculture Rice--Transplanting |
| Note | A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. IR-93-06 |
| Abstract | A field experiment was conducted on a heavy clay acid sulphate soil with (Smectite) clay mineral, during the dry season from December 1993 to May, 1994 at the Regional Experimental Centre, AIT. Total number of treatments were six with four replicates in each of the treatments. The treatments consist of three land preparation methods· viz. transplanted rice, pregerrninated seeds broadcasted on puddled soil (wet seeding) and dry seeds broadcasted on un-puddled soil (dry seeding) with two types of urea viz. urea and neem coated urea. The design of the experiment was a Completely Randomized Design. In wet and dry seeded rice treatments permanant submergence was started from 17 DAS. Actual ET, vertical percolation losses, lateral seepage losses, land preparation water requirement, total water requirement and yield and yield components were measured in individual plots. Total nitrogen concentration in grain and straw were determined by Kjeldhal method. Water productivity (WP), Water use efficiency (WUE) and Nitrogen use efficiency (NUB) were calculated for the three land preparation methods. Land preparation required about 18% of the total water requirement in transplanted (206 mm) and wet seeded rice (219 mm). Total vertical percolation was maximum in dry seeding and minimum in transplanted plots. But in dry and wet seeding daily vertical percolation gradually decreased with the age of the crop and it was same as that of transplanted plots at the maturity stage. Total lateral seepage losses did not show any difference among treatments. Total ET in three land preparation treatments were the same. Daily ET at vegetative stage was higher in transplanted rice than wet and dry seeded rice. Furthermore, daily ET was highest at reproductive stage in all three treatments. Total water requirement in dry seeded rice was about 10% less than that of transplanted rice and 5.4% less than that of wet seeded rice. Yield was the same in all three treatments. WP was 3.07 kg ha1 mm1 , 3.65 kg ha1 mm1 and 3.77 kg ha1 mm-1 in transplanted, wet seeded and dry seeded rice, respectively. WUE was highest in wet seeding. But maximum number of man-hours was required in transplanting followed by wet and dry seeded rice. Neem coated urea did not have any effect on yield or NUE. Dry seeded rice can be recommended as the best water, labor and time saving method without any yield reductions provided, the soil has clay with expanding type clay mineral. Further, dry seeding has an advantage that the soil structure is maintained and it gives extended time for the preparation for the second crop since crop matures 15 days earlier. |
| Year | 1994 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ;|vno. IR-93-06 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Irrigation Engineering and Management (IR) |
| Chairperson(s) | Murali, N. S. |
| Examination Committee(s) | Murty, V.V.N ;Kono, Yasuyuki |
| Scholarship Donor(s) | DAAD ; |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 1994 |