* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download the effects of the method of land preparation on the growth
Agroecology wikipedia , lookup
Arbuscular mycorrhiza wikipedia , lookup
Entomopathogenic nematode wikipedia , lookup
Soil horizon wikipedia , lookup
Human impact on the nitrogen cycle wikipedia , lookup
Soil erosion wikipedia , lookup
Surface runoff wikipedia , lookup
Soil respiration wikipedia , lookup
Plant nutrition wikipedia , lookup
Terra preta wikipedia , lookup
Canadian system of soil classification wikipedia , lookup
Soil compaction (agriculture) wikipedia , lookup
Soil food web wikipedia , lookup
Crop rotation wikipedia , lookup
Soil salinity control wikipedia , lookup
Soil microbiology wikipedia , lookup
Sustainable agriculture wikipedia , lookup
No-till farming wikipedia , lookup
Agronomy THE EFFECTS OF THE METHOD OF LAND PREPARATION ON THE GROWTH AND YIELD OF SUGARCANE IN FINE-TEXTURED VERTISOLS AND INCEPTISOLS IN THE CAUCA VALLEY, COLOMBIA Sun Jen Yang and Rafael Quintero D. Colombia Sugar Cane Research Institute I ABSTRACT The objective of this study was to find an effective but also economicalmethod of seed-bed preparation for sugarcane. The experiment was conducted on lnceptisol (Palmeras series), and Vertisol (Galpon series) in the Cauca Valley, Colombia. There were six treatments which involved subsoiling, chiselling, heavy disking and light harrowing. The time required for each operation was recorded and after the completion of the tredtment the depth and the degree of soil disturbance achieved by the operations were measured. Cane growth was measured periodically and the yields of cane and sugar were determined at the time of harvest. To observe residual effects, the trials were continued but only light cultivation was applied to the first ratoon crops. The results indicated that subsoiling produced the deepest soil penetration and the greatest degree of soil disturbance followed by chiselling, while disking had the least effect. The differences in the amount of soil disturbance between the treatments were smaller six months after the operations were carried out. No significant differences were found between the treatments in terms of cane growth, nutrient uptake and final yields for both plant and ratoon crops. Traditional land preparation includes cross subsoiling, cross disking and harrowing but it is suggested that cross chiselling plus harrowing would be more economically effective. INTRODUCTION In Colombia centrifugal white sugars are produced mainly in the Cauca Valley where a total of 135,000 ha of land are cultivated to produce 1.2 million tonnes of cane sugar annually. The soils on sugarcane plantations belong mainly to four orders : Mollisols, Inceptisols, Vertisols and Alfisols. Most of these soils are fine textured with 2:l clay minerals, (IGAV-CVC5). Tillage operations are important not only to produce good soil conditions for cane growth, but they also affect the costs of production significantly. On most sugar estates in the Valley, the standard practices for land preparation are crossdeep subsoiling, disking, harrowing and ridging. Subsoiling is a costly operation, needing high tractor power. Keywords: Land preparati'on, fine textured soil, soil disturbance SUN JEN YANG AND RAFAEL Q W R O D. The effectiveness of this practice is dubious because the soils have good physical characteristics. When the price of sugar reaches the low level that it has reached today, it is essential to reduce the cost of cultural practices as much as possible whilst affecting yields as little as possible. The purpose of this study was to compare standard land preparation methods with other simplified methods in fine-textured Vertisols and Inceptisols. MATERIALS AND METHODS The field experiments in this study were conducted on two soils, a Palmeras clay loam (Vertic Ustropept) and a Galpon clay (Tipic Pellustert). Important physicochemical properties of these two soils are shown in Table I. The Palmeras clay loam is an Inceptisol with a sub-angular blocky structure in the surface 50 cm of soil, and the bulk density is relatively high. It has weak acidity and a medium level of fertility. This soil is located extensively in the southern part of the Cauca Valley. The internal drainage is generally poor because of a high water table. The Galpon clay is a Vertisol with a very fine texture. The soil depth generally exceeds 80 cm and a well developed sub-angular blocky structure can be observed in the surface 70 cm layer. The soil is compacted, the density being relatively high before treatment. Drainage is moderately good and the level of the water table ranges between medium and low. It is weakly acid to neutral, has a medium organic matter content and low phosphorus and high potassium contents in the top soil. The Galpon soil series is widely distributed in the Valley, but is concentrated mainly in the north. The two soils studied contain high percentages of 2:l expansion clays which are mainly Montmorrilonite and Vermiculite. The treatments used involved four operations : subsoiling, chiselling, heavy disking and harrowing. Details of the treatments are shown in Table 11. The experiment was arranged in a randomized complete block design with three replications. The area of each plot varied between 0.3 and 0.9 ha, depending on the site. Old stools were eradicated and land levelling was practised before the treatments were imposed. All the treatments were carried out during the dry season and because the soil moisture was low, conditions were suitable for land preparation. The subsoiling was conducted with a three-shank subsoiler, the shanks being 75 cm apart. It was drawn by a D6 Caterpillar or a Steiger tractor. Chiselling was carried out with a 5-shank ripper drawn by a Caterpillar D5 at San Carlos sugar mill and by a wheel TABLE II. TREATMENTS USED FOR LAND PREPARATION Soil Series Palmeras I I (Vertic Ustropept) Galpon (Typic Pellustert) TREATMENTS USED + 1. subsoiling (2) disking (1) + harrowing (2) harrowing (2) 2. Subsoiling (2) + chiselling (1) 3. Disking (2) harrowing (2) 4. Chiselling (2) harrowing (2) harrowing (2) 5. Subsoiling (1) 6. Plowing + harrowing (2) + + + + tractor at Cauca sugar mill. The tines were 55 cm apart. Twelve disks 90 cm apart were used for heavy disking, the implement being drawn by a D6 Caterpillar at Cauca mill and by 250 HP Steiger at San Carlos. All the harrowing was conducted with an implement made up of 24 disks 65 cm apart drawn by a wheel tractor. For cross subsoiling and chiselling, the two passes were made at an angle of 15" to 20". When conducting the treatments, the time required for and the cost of each operation were recorded and the penetration depths achieved by the implements were observed. After the completion of all the treatments, cane variety C P 57-603 was planted. The methods of fertilization, weed control, irrigation and other cultural practices were those followed conventionally by the sugar mills. Two months after land preparation was completed, soil cores were taken from each 10 cm or 20 cm layer in the surface 60 cm of soil in each plot to determine soil bulk densities. T o evaluate the effects of treatments on cane growth, populations were counted and stalk length was measured when the crops were 3 and 6 months of age. Top Visible Dewlap (TVD) leaves were sampled at 6 months to determine any effects on nutrient uptake. The leaf samples were dried, ground and analyzed for N, P , K, Ca and Mg. Rooting characteristics were observed by exposing the roots in the surface 80 cm of soil when the crop was 6 months old. The crops were harvested at 14 months of age and the number and the length of millable stalks, and the cane and sugar yields were determined. To observe the residual effects of land preparation practices, the experiments were continued into the first ratoon crops. Only light cultivations were conducted after harvest of the plant crops to avoid unnecessary disturbance of the soil. The growth nutrient uptake and final production of the crop in each treatment of the first ratoon were measured. EXPERIMENT RESULTS The depth of penetration of each implement, the time required and the cost for each operation are shown in Table 111. Because the two sugar mills had different tractors and implements, the times required and the costs were not directly comparable. In general, subsoiling produced the deepest penetration and the largest amount of soil disturbance, followed by chiselling, and disking or harrowing had the least effect. Soil bulk densities measured two months after treatment showed a similar trend (Table IV). It was apparent that when soil moisture content was low, subsoiling produced the greatest shattering effect, loosening any compact soil layers. However, subsoiling was an expensive operation taking more time and costing more per unit area than the other operations. Unless the increase in cane production due to subsoiling compensates for the cost. the operation would not be economically justifiable. When the plant crop was six months old, root distribution was observed and growth measurements were conducted. The results indicate that in all the treatments most roots were conxentrated in the surface 30 cm layer directly under the cane stool. Only a few roots were found at depths below 30 cm or midway between two furrows. 124 TABLE IV. AGRONOMY EFFECT O F DIFFERENT METHODS OF LAND PREPARATION O N SOIL BULK DENSITY TO A DEPTH OF 50 CM TWO MONTHS AFTER TREATMENT Bulk density (glcm3) TREATMENT 0-10 cm10-20 cm20-30 cm30-40 cm40-50 cm (Table II) Site Hda. La Cecilia I. Cauca 1. 2. 3. 4. 5. 6. Hda. Campo Alegre I. San Carlos 1. 2. 3. 4. 5. 6. TABLE V. EFFECTS OF DIFFERENT LAND PREPARATION METHODS O N GROWTH AND LEAF NUTRIENT CONTENTS O F PLANT CANE 6 MONTHS OLD. Site TREATMENT (Table II) Hda. La Cecilia I. Cauca 1. 2. 3. 4. Hda. Campo Alegre I. San Carlos 1. 2. 3. 4. 5. 6. *'I 5 , Population (1031ha) Stalk length (cm) 63 65 63 61 176 173 180 174 2.10 2.09 1.99 2.12 0.17 0.17 0.16 0.17 1.06 1.13 1.12 1.20 75 73 69 71 76 71 160 159 166 165 160 156 2.22 2.08 2.09 2.11 2.11 1.94 0.25 0.27 0.26 0.24 0.25 0.24 1.38 1.32 1.27 1.24 1.33 1.33 TVD leaf nutrient NO/o P % K % At both sites, the treatment involving cross subsoiling and disking caused the amount of roots in the surface 20 cm to 30 cm soil layer of soil under the stool to be greater than in the other treatments. There was not a consistent indication that rooting was correlated with the depth to which an implement penetrated the soil. I t I 125 SUN JEN YANG AND RAFAEL QUINTERO D. TABLE VI. EFFECT OF METHOD O F LAND PREPARATION ON CANE AND SUGAR PRODUCTION IN THE PLANT CROP Site Hda. La Cecilia I. Cauca TREATMENT Millable (Table II) Stalks (1031ha) 1. 2. 3. 4. 5. 6. 64.5 65.7 64.3 60.6 65.3 62.8 NS Stalk length (cm) 284 29 1 286 279 291 295 NS Cane Sugar yield yield (tonslha) (tonslh a) 142 137 139 139 135 135 NS 15.3 16.0 16.4 15.9 16.3 14.8 NS Hda. Campo Alegre I. San Carlos There were no statistically significant differences in population stalk length or leaf nutrient contents of the plant crop at both sites following the different soil treatments (Table V). Since treatments did not affect the growth or the nutrient uptake of the crops, it is not surprising that no significant differences in cane and sugar yields due to land preparation were observed (Table VI). However, the traditional method of cross subsoiling plus disking or chiselling did produce slightly higher cane yields than the other treatments. The disk plowing treatment, on the other hand, caised the yields to be lowest. After the plant crops were harvested, the experiments were maintained using light cultivation during the first ratoon in order to observe any residual effects of land preparation. The results of growth measurements conducted when the crop was six months old indicate that, as in the plant crop, no statistically significant differences between treatments could be observed (Table VII). The N contents of the leaves were a little lower than in the plant crop, but there were no statistically significant differences in leaf nutrient contents between the treatments. The harvest results shown in Table VIII indicate that n o significant differences between treatments were found in number and length of millable stalks and cane and sugar yields of ratoon crops. However, the treatments associated with subsoiling still had a slightly higher production and disk plowing had the lowest. DISCUSSION In many sugarcane producing areas of the world, deep tillage, which can be achieved by plowing, subsoiling or chiselling, is believed to be necessary to produce 126 AGRONOMY TABLE VII. RESIDUAL EFFECTS OF METHOD OF LAND PREPARATION ON THE GROWTH AND LEAF NUTRIENT CONTENTS OF FIRST RATOON CANE SIX MONTHS OLD Site TREATMENT Popula(Table II) tion (1031ha) (Cecilia 6) I. Cauca N % P % K O/O Ca % Mg % 1. 2. 3. 4. 5. 6. I (Campo Alegre 7) I. San Carlos TABLE VIII. Stalk length (cm) 1. 2. 3. 4. 5. 6. RESIDUAL EFFECTS OF LAND PREPARATION METHODS ON THE YIELDS OF THE FIRST RATOON CROP Site TREATMENT (Table II) Millable stalks (1031ha) ~ta% ~e"~th (c$) Hda. La Cecilia I. Cauca I. 69.9 242 Hda. Campo Alegre I. San Carlos 1. 2. 3. 110.3 104.0 100.8 251 239 248 Cane yield (tonslha) Sugar yield (tonslha) 110 17.1 I SUN E N YANG AND RAFAEL Q W R O D, 127 high crop yields. The purpose of deep tillage is to break up compact subsoil layers or hard pans to permit deep root penetration. However, the effectiveness of deep tillage varies from soil to soil, from place to place and from year to year. The need for deep tillage, therefore, has been questioned for more than 50 years. SavesonI3 reported that deep ploughing and subsoiling produced the greatest increase in sugarcane yields on fine sandy loams and silty loams, but no responses were obtained on silt loams and clay alluviums. Ricaud12 conducted experiments on Commerce silt loam soils in Louisiana and found that a 19% to 40% increase in cane yield resulted due to subsoiling. Deep tillage in a Pullman clay loam (Torrectic Paleustrolls) in the Southern High Plains of the U.S. increased water intake and storage in the soil profile, leading to higher yields of wheat, sorghum and corn ) ) Taiwan, . subsoiling to a depth of 45 cm increased (Musick8, Musick and ~ u s e k ~In cane yield 20% to 30% in the plant crop in comparison with the conventional shallow tillage of 30 cm in unirrigated clay soil, but the residual effect lasted only to first ratoon, no increase being observed thereafter (Chengl). Subsoiling has been used widely on Hawaii sugarcane plantations. The main purpose is to reduce surface erosion and runoff in non-irrigated areas. In irrigated areas, subsoiling is employed prior to plowing in order to obtain better penetration and granulating action of disk plows (Trouse and Humbert14). Plowing and subsoiling to depths up to 100 cm have been tested on 10 different soil series in the South African sugar industry. The results obtained indicate that deep tillage did not produce better cane yield than the conventional plowing to a depth of 20 cm ~ , ~Pearsonu). to 25 cm ( M ~ b e r l y and Experimental results obtained from Brazil ( ~ e r n a n d e s ~show , ~ ) that subsoiling was effective only on soils with compact layers. On a dark Latosol, subsoiling to a depth of 60 cm to 70 cm actually caused cane production to decrease. The results obtained in this study show that different methods of land preparation did not produce signfficant differences in cane and sugar yield on an Inceptisol and a Vertisol in the Cauca Valley. Both Inceptisols and Vertisols are fine textured soils with well-developed sub-angular blocky structure in the surface 45 cm to 70 cm soil layer. Although the bulk densities of the soils are high, cracks between structural units are sufficient for water to enter and for the exchange of air between soil and atmosphere. They also provide channels for root growth. Furthermore, more than 90% of sugar cane plantations in the valley are irrigated, and the main purposes of deep tillage fall away under such conditions. Fine textured soils generally maintain a high moisture content, especially during the rainy season and they have a high water table level, which is common in the valley. Subsoiling or chiselling in a moist or wet soil has no shattering effect to loosen the soil. On the contrary, there may be a puddling action which tends to seal the grooves made by the shoe of an implement (Baver2). As reported by Trouse and Humbert14 from Hawaii, shear plane development in a wet soil was obtained to a depth of less than 15 cm and plastic flow shear extended for the rest of the depth of subsoiling. As a result, rain or irrigation water ran into the subsoiler paths and accumulated there, causing poor local aeration and drainage. I 128 AGRONOMY Cost is another important factor to be considered in deciding on the method of land preparation. Deep tillage uses a lot of power. Nichols and Reeves1° pointed out that the major factor in power requirement is the horizontal pressure of the implemerlt against the soil, which increases the force required for fragmentation or shear. When soil is dry and suitable for subsoiling, power consumption is high because of large cohesive forces. In the Cauca Valley, subsoiling is done mostly by high power Caterpillar crawler tractors or Steiger 250 H.P. tire tractors. The cost of a standard land preparation which includes cross subsoiling, disking and harrowing is 25% to 80% higher than the simplified method of cross disking or chiselling plus harrowing. Since deep tillage did not increase yields significantly, the extra costs are considered to be unwarranted. CONCLUSION The deep tillage of soils of fine texture with well-developed structure in the Cauca Valley is considered to be unnecessary. At all events, subsoiling should not be used universally without regard to the soil properties. The standard land preparation method of cross subsoiling, cross disking plus harrowing has not only low efficiency as far as operating time is concerned, but it is also costly. The practice should be used only in soils where root development and water movement are restricted by dense compact layers in the profile. For soils without restrictions, cross disking plus harrowing can be used instead to maintain good soil tilth to a depth of 25 cm to 35 cm. When preparing land during the dry season in some soils where the surface layer is very hard, one pass of a subsoiler may be added in order to achieve the desired depth of tillage by disking. REFERENCES 1. Cheng, Chlh (1968). Study on the methods of land pleparation for sugar cane (in Chinese). Rep. Taiwan S u g a ~Res. Inst. 45:71-96. 2. Baver, L.D., Gardner, W.H. and Gardner, W.R. (1982). So11Physics 4th ed., John Wiley & Sons, Inc., New York. 3. Fernandes, J . D . , Furlan1 Neto, V.L., and Stolf, R. Subsolador alado como implement0 de preparo de solo para a cana-de-acucar. Trabalho presentado No. XVIII Cong. Bras. Cienc~ad o Solo. 4. Fernandes, J.D., Camposilvan, D., Furlani Neto, V.L. and Reicha~dat,K. (1977). Soil preparation fol sugarcane. Proc. I\SSCT. 16:1113-1121. 5. IGAC-CVC (1982). Semi-detall soil survey of Cauca V a w . _ 6. Mobeily, P.K. (1942). Deep tillage investigations on five soil types of the South Afrlcan Sugarbelt. Proc. S. Afr. Sugar Technol. Ass. 46:205-210. 7. Moberly, P.K. and T u ~ n eP.E.T. ~, (1977). The minimum tillage system for re-establishing sugarcane fields. Proc. ISSCT. 16: 1377-1382. 8. Musick, J.T., Dusek, D.A. and Schneider, A.D. (1981). Deep tillage of irrigated Pullman clay-loam a long term evaluation. Transactions of the ASAE. 24:1515-1519. 9. Mus~ck,J.T. and Dusek, D.A. (1975). Deep tillage of grade furrow irrigated Pullman clay loam. Transactions of the ASAE. 18:263-269. 10. Nichols, M.L. and-Reaves, C.A. (1958). Soil reaction : to subsoiling equipment. Agr. Eng. 39. 39:340-343. 11. Pearson, C.H.O. (1963). The results of an observation trial to test the degree of cultivation necessary to re-establish sugalcane. SASA Experiment Station. SUN EN YANG AND RAFAEL QUINTERO D. 129 12. Ricaud, R. (1977). Effect of subsoiling on soil compaction and yield of sugarcane. Proc. ISSCT. 16:1039-1048. 13. Saveson, I.L., Lund, Z.F. and Davidson, L.G. (1966). Deep tillage investigations on alluvial soil in the sugarcane area of Louisiana. USDA. ARS : 41-123. 14. Trouse, A.C. and Humbert, R.P. (1959). Deep tillage in Hawaii 1. Subsoiling. Soil Sci. 88:150-158.