AGRO 3503, Unit III-3, Fertility and Water Management of Rice.


Information on these questions can be found in Chapters 8 and 9 of MP192, Univ. of Arkansas Rice Production Handbook.


1. If applying N fertilizer in a 2-way application program to ‘Cypress’ on a soil

    previously cropped to corn, the recommended pre-flood rate (lbs/acre) is:

            A. 75                           B. 90                            C. 100                         D. 85


2. If the midseason rice plant gauge for ‘Wells’ variety averages 700 cm2, the

    recommended mid-season N rate is:

            A. 0                             B. 30                            C. 45                           D. 60


3. Recent research has shown more efficient N management with newer cultivars by:

            A. using a 3-way split                                         

B. using only a 2-way split

            C. omitting pre-flood N, using mid-season N monitoring instead

            D. a single pre-flood N application followed by mid-season N monitoring


4. When applying urea pre-flood, it is recommended to flood:

            A. within 2 weeks                                     B. before applying

            C. within 5 days                                        D. flooding is generally not needed


5. Pre-flood N application is generally more efficient if:

            A. applied to dry soil                                           B. applied to muddy soil

            C. applied to a shallow flood                            D. applied using 32% liquid N


6. The efficiency of mid-season N applications is about:

            A. 10 – 25%                                                     B. 25 – 65%

            C. 65 – 80%                                                     D. 80 – 95%


7. If using poultry litter on cut areas of fields, the recommended N rates are:

            A. 30 lbs less than normal                          B. 30 lbs more than normal

            C. 0 lbs/acre                                                            D. the same as normal


8. Initial symptoms of Zn deficiency in rice are:

            A. basal chlorosis of leaves                                   B. firing of leaf tips

            C. tall, spiny, yellowed plants                           D. stunted, purple tinted plants


9. Sulfur fertilization of rice is most likely needed:

            A. when rice follows corn                              B. on clayey soils

            C. on sandy soils                                            D. on soils with pH > 6.5


10. Salinity damage to rice on soils with a history of salt damage is enhanced by:

            A. using no-till                                           B. excess lime

            C. using a chisel plow                                         D. growing semi-dwarf varieties


11. It is recommended that irrigation water supply be enough to:

            A. flood in 5-7 days                                         B. flush in 12 hours or less

            C. maintain a 6-8 inch flood                                 D. flood in 3-5 days


12. If you have a 50 acre field of clay soil, the recommended pump supply is at least:

            A. 600 GPM                                                    B. 1000 GPM

            C. 800 GPM                                                    D. 750 GPM


13. If the pump capacity of a 60 acre rice field is 1500 GPM, it will take about how

      long to apply a 4 inch flood?

            A. 24 hrs                                                        B. 39 hrs

            C. 72 hrs                                                        D. 76 hrs


14. What is the GPM of a 10 inch inside diameter pipe emitting water that has a

       12 in length for a 8 in drop plumb bob?

            A. 600                         B. 800                          C. 1000                D. 1200


15. Over 50% of the total cost of operation over the life of an irrigation system in

      in rice is:

            A. energy costs                                         B. repair costs

            C. maintenance costs                                        D. depreciation costs


16. Which of these soils holds water for rice the best?

            A. silt loam with a pan                                    B. silt loam

            C. clay                                                             D. sandy loam


17. A major contributor to high EC rates in water is:

            A. high bicarbonates                                         B. high chlorides

            C. high SAR                                                     D. high Zn levels


18. If pumping capacity is 1200 GPM for a 60 acre field, what should the delivery

      rate be to a 7 acre paddy if using multiple outlet design?

            A. 80 GPM                                                    B. 140 GPM

            C. 120 GPM                                                    D. 160 GPM


19. What are four of the most important keys to rice water management?