The Effect Of Regulated Deficit Irrigation On The Growth, Physiology-Zoology And Yied Of Brazil Upland Rice IAPAR9

The thesis aims at exploring the water demand during the growth stages ofBrazilian Up-land RiceIAPAR9 and its effects on the growth, physiology-zoologyand yield during different periods and under various soil moisture. Studying thisproblem by the theory and method of regulation dificit irrigation(RDI). Results are asfollows:1. During the course of germination, its velocity, power, rate, index, regulation degreeand vitality index are differently receded with the lowering of the soil moisture.Comparatively, the indexes under the condition of 80% moisture content excel thoseof other processing's. In regard to the strong seedling body character, the processingin 50%-70% moisture content is better. The characters of seedling are all relative tosoil's moisture content, and root length, root hat length ratio, root weight, stem weight,fibre number are closely related to the soil moisture. With the soil moisture contentrate descending its germination power, the seed vitality are accordingly lowered indifferent degrees; the seedling body character also presents obvious differences. Theyoung sprout root hat is bigger under 60%-80% water humidity content, and the mainroot and fibres are more developed, which is a more ideal stub type. So inseminationunder the condition that soil contains the water to measure for 80%, the germinationperiod above 60%, thus it is saved not only with 20% of the water, but also canacquire good seedling body character.2. The dissimilarity of the soil moisture content in the former periods has greatinfluence on the root's growth in the late periods. Except for the root length, the rootnumber, root volume, root weight and root hat ratio increase more quickly under thecondition of the lower soil moisture content in the former periods but the higher in thelate periods. The root number and root volume processed in C₇ attain the biggest value,separately 84.61 pieces and 30.01cm³, 55%-65%, 55%-65%, 70%-80% soil moisturecontents in response to each stage; the root weight and the root hat ratio of the C₉processing attain the biggest value, 9.63g and 37.52%, and 55%-65%, 65%-75%,70%-80% soil moisture contents during each stage. The root length increases in theshape of beeline with the soil moisture content, appearing closely related to it. Therate increased in the third period is the biggest. The C₁₉ processing attain the max40.37 cm, 75%-85%, 75%-85%, 80%-90% soil moisture content in each stage.Root-shoot ratio matches the increment of the photosynthesis velocity.3. The soil moisture content dissimilarity has a great influence on Brazilian DryRice's physiology index. The transpiration rate, the photosynthesis rate, the pore conducting degree increase obviously, but CO₂ densities between cells lowered clearlyunder the condition of the lower moisture content in the former periods but thehigher in the late periods.. When the soil moisture content in the first stage is55%-65%, the second stage 65%-75%, the third stage 70%-80%, this phenomenonexpresses most obviously, which indicates that Brazilian Dry Rice IAPAR9s has thestronger repair growth effect. Adopting certain measures to increase the CO₂ densitiesappropriately in the experiment, it is advantageous to the increment of thephotosynthesis rate. Transpiration rate and photosynthesis rate present the non-linerelation. Photosynthesis rate will stop when the transpiration rate attains a certainvalue, and a suitable measure should be carried on to control the transpirationbeyond the critical value, reducing the loss of the moisture.4. When the transpiration rate are separately 3.4021 mmolH₂Om^-2s^-1 and 3.0057mmolH₂Om^-2s^-1 (actual value: 3.63 mmolH₂Om^-2s^-1, 2.46 mmolH₂Om^-2s^-1), thephotosynthesis rate attains the biggest value 8.5520μmolCO₂m^-2s^-1 and 24.2752μmolCO₂m^-2s^-1 (actual value: 8.58μmolCO₂m^-2s^-1, 24.15μmolCO₂m^-2s^-), and itindicates that the photosynthesis rate can be increased by means of increasing thetranspiration rate during the period of booting- full heading.5. The valve values of pore conducting degree are 0.0986 molH₂Om^-2s^-1 and0.1489 molH₂Om^-2s^-1. If smaller, it will not be good for transpiration andphotosynthesis; if higher, it doesn't benefit for water saving.6. N, P, K chemical element contents are subjected to the influence of the soilmoisture content of the former periods, thus the sequence of the size as K＞N＞P,presenting a close relationship. For the first stage, the most advantageous soilmoisture content for N, P, K absorbing is 65%-75%; For the second stage, the mostadvantageous soil moisture content for N, P, absorbing is 75%-85%, and 65%-75%for K, [In response to the first stage, the soil moisture content is: A₁(45%-55%)for Nand K; A₂ (55%-65%) for P]; for the third period the most advantageous soil moisturecontent for N, P, K absorbing is 70%-80%. [In response to the first and the secondperiods the moisture contents are: A₂ (55%-65%) and B₄ (55%-65%) for N, A₂(55%-65%) and B₆ (75%-85%) for P, A₂ (55%-65%) and B₅ (65%-75%) for K.].7. The water use efficiency (WUE), yield (Y) the water supply quantity (X)present an obvious non-line relationship. The best value of the water use efficiency isnot achieved under the condition of the full supply of water and the highest yield. Thewater use efficiency of leaf should control the evaporating rate below the criticalvalue in case of extravagant evaporation. The infusing amount of water should carryon the reasonable allotment during each growth period, to assure the water supply quantity in the sensitive period, to be advantageous to the increase of the water useefficiency. The water demand, mold ratio coefficient are comparatively bigger duringthe course of spike pregnancy and spike uniform, so Brazil land-up Rice is mostsensitive to the soil moisture in booting- full heading, in turns, tilling - booting＞seeding-coming out＞coming out -tilling＞full heading-mature.8. The yield of the C₁₀ processing is the tallest, 5015.5 Kg in terms of theory,accordingly, the soil moisture content for the first stage is 55%-65%; 65%-75% forthe second stage and 80%-90% the third stage. The actual yield of the C₉ processing isthe tallest, 4799.9 Kg, accordingly the soil humidity content for the first stage is55%-65%, 65%-75% the second stage and 70%-80% the third stage.The actualhihgest yield consumes the amount of water(6868.3 m3.hms-2s) to onsume theamount of water(8507.2 m3.hms-2s) with full irrigation to compare, the stanza water1638.9 m³.hm^-2, can saving water 23.86%, yield is increased by 12.28%.9. When the measure of irrigation water is the 6368.96 m³.hm^-2, the WUE ishihgest(0.7941); When the measure of irrigation water is the 6907.92 m³.hm^-2, theyield is hihgest,(7854.53 Kg.hm^-2).So the measure of irrigation water is propercontroling between the 6368.96 m3s and 6907.92 m³.hm^-2,with full rrigation(8507.20m³.hm^-2) to compare, it can save irrigation water 23.16%-33.57%.The on theory yieldand actual yields in the amount of water is exactly in this scope. The mold ratio of Brazilland-upIAPAR9 is: seeding-coming out 9.56%, coming out-tilling 14.30%, tilling-booting20.02%, booting- full heading39.65%, full heading-mature 16.47%.10. See from the main factors composing yield: the weight of one thousand grains ismainly subjected to the influence of the photosynthesis velocity; the grains number, validspike are mainly subjected to the influence of water consumption. Under the situation ofthe experiment the sequence of composing factors the yield subjected to is grainsnumber＞valid spike＞the weight of one thousand grains.11. The sensitive degree of Brazil land-upIAPAR9 to the soil moisture in the eachstage is: booting- full heading＞tilling-booting＞seeding-coming out＞coming out-tilling＞full heading-mature. So we can get Jensen model of Brazil land-upIAPAR9: Y_a/Y_m=(ET_a1/ET_m1)^0.0971×(ET_a2/ET_m2)^0.0816×(ET_a3/ET_m3)^0.2469×(ET_a4/ET_m4)^0.2624×(ET_a5/ET_m5)^0.0198...