• Journal of Biosystems Engineering
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• v.40 no.4
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• pp.314-319
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• 2015

Purpose: The ratio of straw to grain mass as a function of cutting height affects combine efficiency and power consumption and is an important input parameter to combine simulation models. An equation was developed to predict straw to grain ratios for wheat as a function of cutting height. Methods: Two mass functions, one for straw and one for grain, were developed using regression techniques and measured data collected in west Texas during the summer, and used to predict the straw to grain ratio. Results: Three equations were developed to facilitate the simulation of a combine during wheat harvest. Two mass functions, one for straw and one for grain, were also developed; a quadratic equation describes the straw mass with an $R^2$ of 0.992. An S-shaped curve describes the mass function for grain with an $R^2$ of 0.957. An equation for straw to grain ratio of wheat was developed as a function of cutting height. The straw to grain ratio has an $R^2$ value of 0.947. Conclusions: In all cases, the equations had $R^2$ values above 0.94 and were significant at the 99.9 percent probability level (alpha = 0.001). Although all three equations are useful, the grain mass and straw to grain ratio equations will have direct application in combine simulation models.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.191-196
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• 1999

In rice-barley cropping systems, efficient utilization of barley straw is essential, both to improve the soil fertility and to conserve the environment. In order to identify the effects of barley straw mulch rates in rice cultivation, a rice cultivar, 'Gancheogbyeo', was directly seeded on a no-tillage field synchronized with barley harvesting with five barley straw mulch rates, i.e., 0, 2.5, 5.0, 7.5 and 10.0 ton h $a^{-1}$ and agronomic characters of rice and soil nitrogen were determined. The increasing of barley straw mulch rates. Dominant weed species, chestnut, occurred in large amounts in no mulching or lower mulch rates than in higher mulch rates. The content of N $H_4$$_{＋}$-N in soil applied with high barley straw mulch rates was lower during the month after seeding, and then it was higher at heading date, compared with lower mulch rates or no mulch plot. As the barley straw rate increased, maximum tillering stage was delayed, and plant height was reduced. Although the lodging of rice plants was seldom observed in all plots, the breaking strength of the culm was significantly higher in the mulch rate of 10.0 ton h $a^{-1}$ . With an increase of barley straw mulch rate, the effective tillering rate and spikelet number $m^{-2}$ decreased while ripened grain ratio increased. The rice grain yield was slightly decreased with an increase of barley straw mulch rate, although significant differences were not found all barley straw mulch rates. These results suggest that there is no significant yield loss although the total barley straw production, approximately 5.0 ton h $a^{-l}$ in the present study, apply in the paddy for the following rice cultivation by no-tillage direct seeding.ect seeding.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.676-685
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• 1993

A mathematical model was developed to quantify the separation process of threshed grain-straw mixtures. It was made to predict the separation loss from a separation unit consisted of stationary crimped sieve with rotating inner rotor. Experiments were performed to prove the mathematical model by changing various levels of pertinent variables for rice. Good Agreement between the simulated results and observed data under the various test conditions, such as inclination angle of the separator, vane pitch, rotor speed, MOG/G ratio, feed rate, and crop variety and moisture content, were confirmed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.2
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• pp.11-26
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• 1964

The studies reported herein are on the varietal differences of rice in the effects of seeding times and nursery periods on the components such as, culm length, ear length, number of ears, ear weight, straw weight, and grain/straw ratio following the first series of studies on heading date. In the present investigations, 50 rice varieties, as the preceding studies, were seeded nine times at the interval of 15 days from March 15 to July 28 in 1963. Each variety seeded at respective time was transplanted in 40 days in nursery after seeded. Reviewing the result obtained from the first series of the studies on heading date, the number of days required to heading from seeding were decreased by delaying the seeding time. Most varieties tended to decrease in the number of days from seeding to heading by the 8th planting time. Some of varieties seemed to be decreased in the number of days from seeding to heading by 9th seeding time. However most varieties were failed to show heading delaying the seeding date at the 10th seeding. The results on the effects of altering the seeding time on the components and varietal differences of the response are summarized as follows; 1) Culm length; It appeared that culm length was shortened when the number of days from seeding to heading was decreased by delaying the seeding date. The varieties which needed many days to heading were also shortened in their culm length. 2) Ear length; Ear length was also shortened when the number of days needed tocheading was decreased, by delaying the seeding time. The varieties which needed many days for heading were also shortened in their ear length, while those which headed earlier seemed to be lengthened in their ear lengths. 3) Number of ears; It was shown that the number of ears was increased with the delay of the heading date, whereas, at the 9th seeding the number of ears was decreased when delayed the heading date. 4) Ear weight; Ear weight per hill was also likely to be heavy throughout the seeding times and varieties except the 7th and 8th seedings in which it appeared to be light on the contrary. 5) Straw weight; Straw weight became heavier as delayed the seeding date throughout all the varieties and seeding dates. 6) The grain/straw ratio; The grain/straw ratio was gradually increased by the 5th seeding time, reaching the pick at 5th. An examination of the varieties at each seeding date showed that the grain/straw ratio was low from 1st to 3rd seeding and from 7th to 9th seeding, when the number of days required to heading from seeding are increased. At the 4th seeding time-which is standard seeding time-5th, and 6th seeding times the ratio was high with the delay of heading.

• Korean Journal of Organic Agriculture
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• v.7 no.2
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• pp.189-195
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• 1999

Under the no-till direct-sown rice-vetch cropping systems, where whole chopped rice straw were returned to the paddy surface at combine harvest and whole-plant of Chinese Milk Vetch(Astragalus sinicus L.) was submerged after direct-sowing, three levels of nitrogen top-dressed(0, 2, 4 kg N/10a) without basal N and two levels of sowing rate were applied into the paddy field in expectation of the enhancement of nitrogen efficiency and protection of agricultural environment in reduced N-fertilizer level. A cultivar, Dongjin, was direct-sown on May 30, 1996. Characteristics of rice growth and physicochemical properties of rice plant were observed. Under the system, reduced total N(4 kg N/10a) resulted in high panicle numbers. N-top dressed toward at later growth stages enhanced the ratio of panicle-producing tillers and at spikelet numbers per panicle. As N-level increases, DM yields of leaf and stem at heading were increased. Maximum grain yield was obtained at 4kg N/10a and major attributed factors to grain yield in this case were the number of grains per unit area and the ratio of ripened grain.

• Journal of Biosystems Engineering
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• v.16 no.1
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• pp.18-26
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• 1991

This study was undertaken to investigate the ratio and compositions of tailings of the tailings return unit in the commercially available head-feed combines. The ratio of the returned tailings to the sum of the threshed grain and the returned tailings was 2.3~7.2% for various varieties of rice and operational conditions of combines tested and increased as the feeding rate and the cleaning air volume increased. The analysis of the returned tailings showed that the composition of rubbish and short straw was decreased as the feeding rate and the cleaning air volume increased.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.2
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• pp.107-113
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• 1973

A pot experiment on paddy rice was carried out to investigate the effect of temperature after heading with application of phosphate, potash and silica on the yield and nutrient uptake. The results obtained are as follows: 1. The Grain yield was greatly affected by temperature during ripening. The yield at $20^{\circ}C$ and at $15^{\circ}C$ decreased to 62.3% and to 37.2% of that at $25^{\circ}C$ respectively. However, the application of phosphate, potash and silica at transplanting increased the grain yield even at low temperature of $15^{\circ}C$. 2. Percentage of ripened grain and weight of 1,000 grains decreased with decreasing temperature but they were increased by the application of phosphate, potash and silica at the low temperature of $15^{\circ}C$. 3. The grain filling rate was fast in the early stage of ripening at high temperature while it was fast in the later stage at low temperature. Low temperature damage was severe in the early stage of ripening. 4. Accumulation of carbohydrate in the grain was small at low temperature of $15^{\circ}C$ and the application of phosphate, potash and silica was effective to increase carbohydrate content in the grain at low temperature. 5. The content of T-N and $P_2O_5$ in straw grown at low temperature were high whereaas those of $K_2O$ and $SiO_2$ were low which were increased by the application of potash and silica. 6. There was a positive correlation between the grain yield and rate of ripening, 1,000 grain weight, contents of $K_2O$ and $SiO_2$, $K_2O/N$ and $SiO_2/N$ ratio, but a negative correlation between grain yield and contents of T-N and $P_2O_5$ in the straw at harvesting stage. 7. Ripening rate and weight of 1,000 grains showed a significant positive correlation with $K_2O$, $SiO_2$, $K_2O/N$ and $SiO_2/N$ ratio in the straw. Further, there was a negative correlation between ripening rate and the contents of T-N and $P_2O_5$ but a positive correlation between weight of 1,000 grains and these elements.

• Journal of Biosystems Engineering
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• v.11 no.2
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• pp.31-40
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• 1986

Cylindrical and conical types of grain-straw separation equipment which has a stationary crimped sieve drum with rotating inner rotor were constructed. The developed equipments were tested to investigate the characteristics of separating performance under various mechanical conditions and crop conditions. As increase of the inclination of equipment and decrease of pitch of cover vane, the grain recovery was increased while straw rejection was decreased. The grain recovery and overall efficiency were decreased as the rotor speed and feeding velocity were increased for both varieties of rice, moisture contents, and test equipments. Conical prototype equipment performed higher straw rejection, lower grain recovery, and lower power requirement. However, separation performance of conical type equipment was more widely varied with various test conditions compared to cylindrical one. The performance of both equipments showed relatively insensitive to crop feedrate and crop properties, such as variety, moisture content, and grain-to-straw ratio.

• Korean Journal of Agricultural Science
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• v.35 no.1
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• pp.101-118
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• 2008

This paper reviews the present situation of Triticale cultivation and examines the potentiality of contribution to livestock as well as poultry sector in Bangladesh Agriculture. Triticale is a human-made cross between rye and durum wheat that has the ability to produce quality green fodder, and then re-grow after first and second cutting to produce grain. In Bangladesh, it is a non-traditional cereal that grows well during the cool and dry Rabi season (November-March) when fodder and feed scarcity is a major limiting factor for ruminant livestock. In Bangladesh Triticale was started to grow in the late Ninety's. The scientists of Bangladesh Agricultural Research Institute (BARI) were first introduced triticale in Bangladesh. Still now the situation of Triticale is grown as fooder and feed in Bangladesh within the scientists under trial. High quality grass fodder was obtained by cutting green triticale plants twice, at 35 and 50 days after seeding, while later the ratooning tillers produced grain to a yield of 1.1-2.4 t/ha of grain for poultry feed or human food. Triticale straw was twice as nutritious as rice or wheat straw and its grain contained more protein than other cereals. Researchers and farmers have also successfully made triticale hay and silage from a mixture of triticale green cuttings, rice straw and molasses. A feeding trial at Bangladesh Livestock Research Institute(BLRI), Savar station showed a large(46%) increase in cow live weight gain and a 36% increase in milk yield (but no change in milk quality or dry matter intake) in cows fed triticale silage compared with those fed rice straw over a period of nine weeks. In another feeding trial, it was found that triticale grain was a good replacement for wheat in the feed blend for chickens in Bangladesh. So it will be a good chance to alive our livestock as well as poultry sector if triticale enters to our existing cropping system as fodder cum grain. The challenge in Bangladesh is to identify fodder technologies that match existing small-scale farmer cropping patterns without needing major inputs or increasing risks. Preliminary field experiments revealed that triticale is a crop with good potential to produce quality fodder and grain for small scale farmers in Bangladesh.

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.145-151
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• 1976

This study was conducted to determine the effect of slaked lime and straw used on the soil pH in the flooded condition and yield of rice grown in AKIOCHI paddy field and their residual effects on the rice plants. The results obtained were summarized as follow: when lime and straw were applied, there was on the average 41% of yield increase over plots treated with three elements of chemical fertilizers. When lime plus straw were used, the growth rate at later stage of rice plant was prominent. Damage due to helminthosporium and blast were found less, the rate of lower-leaf death was low, and grain number, per head, filled grain ratio, and weight of rice grain were higher than control. When lime plus straw were used, higher amount of silicate, calcium, nitrogen and potassium was found in the plants at heading stage. The residual effects of lime plus straw were 20% in the first year, about 10% in the second year and 5% in the third year, respectively. Soil pH was affected by both straw and slaked lime, and it was fixed about 8 days after applying in the flooded condition. The following formulae was suggested from the results in the flooded conditions. $$pH=5.5293+8.6007X_1+2.7836X_2-{6.7422X_1}^2-{1.8522X_2}^2-7.000X_1X_2$$ ($X_1$=slaked lime, $X_2$=straw)