CC BY
44
Section 8. Agricultural sciences
Nurbekov Aziz Israilovich, Khudaykulov Jonibek Bozarovich, Team leader and agronomist, Food and Agriculture Organization Shamukimova Aqida Anvarovna, Sheraliyev Hamidulla Sheraliyevich, Tashkent State Agrarian University E-mail: [email protected]
EFFECT OF TILLAGE METHODS ON PRODUCTIVITY OF FORAGE CROPS UNDER DIFFERENT TILLAGE PRACTICES IN KARAKALPAKSTAN
Abstract. Conservation agriculture practices greatly influence the environment on positive way. Crop rotation is main the principle of CA while short-term cereal-legume crop rotation system is good for farmers and good for the environment as well and also have a great potential to increase agricultural production through implementation of no-till practices. Additionally, short-term crop rotation system can improve soil quality by increasing soil organic matter levels in the upper layers of the soil. Within a crop rotation, different root systems influence different soil horizons and improve the efficiency of the soil nutrient use. In general, the soil structure becomes more stable (Bot and Benites 2005; Suley-menov and Akshalov 2009). The experiment was conducted with the use of randomized complete block design with three replications. Plot area is 100 m2 (20*5). Analysis of variance (ANOVA) used to determine year, treatment and forage yield effect. Crop production under no-till method had a little higher or similar yield compared to the crop yield under conventional tillage. Maximum forage yield of 16340 kg/ha-1 was recorded under no-till pearl millet in 2015 while minimum forage yield, 819 kg/ha-1, was produced by forage pea conventional tillage also in 2016. The results show that introduction of conservation agriculture as a no-till forage crop production will help livestock producers to have access to low-cost forage resources and thus improve the efficiency of livestock production in Uzbekistan, and perhaps in other Central Asian countries as well. This beneficial aspect of crop rotation with integration of livestock sector should be further investigated in the Aral Sea basin.
Keywords: Crop rotation, no-till, dry matter yield, cost benefit analysis.
Introduction Amudarya River, and includes its delta into the Aral
The Autonomous Republic of Karakalpak- Sea was one of the main rice-producing regions in stan (KK), which is located at the tail - end of the the Republic of Uzbekistan. After 1991, focus of
agricultural production of Karakalpakstan did not change, it remains the largest rice-producing region in Uzbekistan, but the productivity of agriculture it-selfhas decreased by 40.0-50.0% due to the increasing soil salinity, leading to billions of Uzbek Soums in annual losses.
Three successive years of drought (1999-2001) have inflicted serious damage on the agricultural sector of Karakalpakstan. Gross production of the three main crops - rice, cotton and wheat fell by 75% and 52%, respectively, in 2001 as compared to 2000. Cotton still dominates irrigated cropping but not to the same extent as in the 1980s. Cereal crops have largely replaced cotton, although potatoes, fruit and vegetables are important in some areas, as private markets have expanded. Alfalfa growing area has decreased considerably in the last 10 years (1994-2004). Sorghum, proso millet and sunflower mostly grown by private sector in Karakalpakstan.
Rice, cotton and wheat are grown either continuously or in crop rotation together. Before independence, cotton was grown in rotation with alfalfa; three years of alfalfa followed by six years of cotton, which has already led to marginal and hardly sustainable soil fertility management. Crop rotation with fodder legumes or pulses is extremely important for soil health and management of plant diseases. The absence of alfalfa in present crop rotations has diminished humus in the soil and considerable micro-nutrients. It has also eliminated natural soil humus content and removed the soil structure benefits derived from alfalfa's root system.
Conservation Agriculture (CA) is defined as a concept for resource-saving agricultural crop production that strives to achieve acceptable profits, high and sustained production levels while concurrently conserving the environment. CA is based on enhancing natural biological processes both above and below the ground. Interventions such as mechanical soil tillage are reduced to an absolute minimum, and the use of external inputs such as agro-chemicals, nutrients of mineral or organic origin are
applied at an optimum level that does not interfere with or disrupt the biological processes. Conservation agriculture system helps to conserve the soil resource by retaining leave plant material on the soil surface along with crop rotation. Thus, crop rotation with dual-purpose forage cereals and legume crops can be good for both, farmers and environment.
As already mentioned in previous paragraphs limited number of forage crops grown by the private sector in Karakalpakstan - mostly sorghum, proso millet and corn. Private farmers use old varieties of sorghum and millet and their seed production is not properly organized. Forage crop yield is low because of poor agronomic practices e.g. sub-optimal seeding rate and fertilization. The above-mentioned problems limit forage production for livestock during the winter period. Growing forage crops for fresh fodder, hay, silage have potential to reduce the feed gaps experienced by many smallholders. There is an opportunity to introduce Sudan grass, field pea, pear millet under no-till to the existing crop production system in the region.
Crops differ for the quantity and quality of the residues they produce, and thus for the effect on soil properties. For example, leguminous crops and oil crops produce fewer residues that decompose faster, have a lower C/N ratio and are easier to manage during direct sowing than cereals. A well-planned crop rotation will help in insect and disease control and will help in maintaining or improving soil structure and organic matter levels. A well-planned crop-rotation system under conservation agriculture can help producers avoid many of the problems associated with traditional tillage such as increased perennial weeds, plant diseases, insects etc. Using a variety of crops, we can reduce weed pressures, spread the workload, reduce and combat soil erosion. Legume crops in the rotation have become more valuable with the increased cost of nitrogen due to their nitrogen fixation capacity. Research and experience have proved that a good crop rotation will ensure more consistent yield and increase profit potential.
Materials and methods tures. The desert and steppes are characterized by short
Uzbekistan has extreme continental type climate, winters with thin and unstable snow cover, and hot dry
with hot dry summers, unstable weather in winter, and dusty summers. The mountains (over 600 m asl) have
a wide range ofvariation in seasonal and daily tempera- high precipitation (up to 600 mm per year).
Figure 1. Mean annual precipitation, Chimbay (2015-2016)
According to the data of the Chimbay Meteo Station, located in Chimbay district, the annual long-term precipitation is 110 mm, distributed as 18 mm in fall (September- November), 60 mm in winter (December-March), 24 mm in spring (April-May), and 8 mm in summer (June-August). The year 2016, in contrast with 2015 was characterized by favourable weather conditions for agricultural crops growth and development. First rainfalls occurred in the middle of the autumn of 2015. It negatively affected the germination of winter wheat and, as a result, percentage of germination was less compare
to the observed in other years. In general, the winter of 2015 was favourable crops growth and development and warmer than usual and almost without snow (Figure 1).
The average temperature in Chimbay district in summer was ranged from +25.2 to +28.7 degrees C (the highest temperature can be more than +40 degrees C) and the highest air temperature was recorded (28.80C) in 2015. In winter there are frosts through the district. During the winter season the air temperature in January month went down - 10.0 degrees C in 2016. (Figure 2).
30.0 25.0 20.0
o
£ 15.0
10.0 5.0 0.0 -5.0 -10.0 -15.0
-2015
-2016
Figure 2. Average air temperatures in Chimbay district (2004-2006)
A cereal-legume crop rotation experiment initiated in 2015 in Shakhob farm, Korauzak district, Karakalpakstan. Within this study five forage crops, received from the germplasm collection of ICRISAT-ICARDA and collected in Uzbekistan, Kazakhstan and Tajikistan, have been evaluated for dual purposes under no-till and conventional tillage (dry fodder and grain) to enhance fodder availability during winter season in Karakul demonstration site, Korauzak district in Karakalpakstan.
The field was ploughed to a depth of 25-27 cm under traditional tillage, which was followed by harrowing, leveling, and opening the furrows at 70 cm spacing while in no-till permanent beds used to sow all crops. Planting rate for each crop was as follows: Pearl millet 5 kg ha-1, sorghum 12 kg ha-1, maize 35 kg ha-1, sudan grass 15 kg/ha and field pea 80 kg ha-1 in both tillage methods. Each plot consisted of 8 rows, 20 m long. At 10 days after planting, seedlings were thinned to single plants spaced at 10 cm in pearl millet and 7 cm in maize. Fields were fertilized with 120 kg/ha of ammonium nitrate 4-5 days after sowing, with a second application of ammonium nitrate applied at the rate 80 kg/ha at 30 days after the sowing, leading to a total 200 kg/ha of ammonium nitrate (nitrogen 34%) application. Hand weeding was done twice, first 10 days after sowing and then at 30-32 days after sowing. Post-planting irrigation was done twice, first irrigation 10 days after sowing and second irrigation 35 days after sowing.
Table 1. -
The experiment was conducted with the use of randomized complete block design with three replications. Plot area is 100 m2 (20*5). Analysis ofvari-ance (ANOVA) used to determine treatment and forage yield effect. Proposed models for crop rotation are as follows:
- No-till - sorghum, maize, pearl millet, Sudan grass and field pea.
- Traditional tillage - sorghum, maize, pearl millet, Sudan grass and field pea.
Results:
There are a few number of experiments conducted to study the role of crop rotation in weed suppression under conventional agriculture systems with herbicides. They studied the impact of different type of herbicide used rather than other factors associated with crop rotation. Liebman and Gallandt (1997) reported that rotation without herbicides have generally more diverse systems with lower density of problem weeds but a greater diversity of weed species (Lovett Doust et al., 1985). This is reasonable, since the variation in cultural practices during the rotation will tend to disrupt the life cycle of each particular weed species but create niches for a greater variety of species.
ANOVA (analysis of variance) shows that crops dry matter yield was significantly affected by years, crops and tillage methods (<.001). Our findings are in line with Kosutic et al. 2005 reports where grain yield ofwinter wheat among conventional, conservation and no-till treatments did not significantly differ.
Analysis of variance
Source of variation d.f. s.s. m.s. v.r. F pr.
Year.TILLAGE.CROPS 19 1.05E +09 5.54E + 07 5.85 <. 001
Residual 40 3.78E + 08 9.46E + 06
Total 59 1.43E + 09
Crop rotation is the main principle of conservation agriculture. Short-term cereal-legume crop rotation system have a great potential to increase agricultural production through implementation of no-till practices. Some newly introduced forage crops are
performed well under both no-till and conventional method in spite of serious drought and salinity in the experimental site.
Dry matter yield under no-till method had a little higher or similar yield compared to the conventional
tillage (Figure 3). Dry matter yields of studied crops ranged 819-16340 kg/ha1. Maximum dry matter yield of 16340 kg/ha-1 was recorded under no-till pearl millet in 2015 while minimum forage yield, 819 kg/ha-1, was produced by forage pea conventional tillage also in 2016. Finally, our results emphasize
the necessity of taking into account the NT method in the cultivation of corn, pearl millet, sudan grass in the irrigated conditions of Uzbekistan to stabilize forage production in the region. The results show that no-till practices are feasible for the production of forage crops dry matter yield.
Figure 3. Effect of tillage method on dry matter yield of different forage crops (2015-2016)
Figure 4. Effect of tillage method on grain productivity of different forage crops (2015-2016)
Based on our experiment it was found that the for- est grain yield (3002) was recorded in 2015 with tradi-age crops grain yield was higher when the crops grown tional tillage with sorghum while the lowest (563) was under no-tillage system in 2016 (Figure 4). The high- recorded in 2015 with traditional tillage in Sudan grass.
Figure 5. Spent fuel for tillage and planting, l/ha
Figure 6. Cost-benefits of different forage crops under no-till and conventional till (2015-2016)
As figure five presents, no-till demonstrated tion (5.4 l ha-1) was obtained with no till Pearl millet,
advantages in terms of conservation of energy and which was 54.0 litres lower than conventional pearl
labour resources. As fuel for producing agricultural millet. Fuel consumption per ha was 76.5, 67.5.6,
products has become expensive farmers in Uzbeki- 58.4, 57.1 and 58.6 litres under traditional tillage
stan has already started alternative ways how to de- system for Corn, Forage pea, pearl millet, sorghum
crease fuel consumption. The lowest fuel consump- and Sudan grass while in no-till Corn, Forage pea,
pearl millet, sorghum and Sudan grass had 8.9, 6.7, 5.4, 5.8, 6.1 litres respectively.
Cost benefit analysis of tested forage crops under different tillage methods in drought and salt affected regions of Aral Sea basin was conducted to estimate economic returns of tested tillage methods for forage crops production. The highest profit was recorded under conventional tillage of Pearl millet - USD907/ha-1, while negative profit was under conventional tillage for Forage pea - USD -59/ha-1 (Figure 6).
Conclusions
The results obtained in this experiment for different methods of forage crops cultivation indicate that tillage reduction in surface irrigated production systems reverberate in the same positive way in terms of production profitability and sustainability
of crop production. New crop rotations with the use of forage crops are recommended to livestock producers to ensure feed for the winter period. The new forage crops under no-till practices can help to improve soil fertility and increase crop productivity. In addition, developed crop rotation schemes including forage crops were recommended to decrease forage shortage during the winter period. The results show that introduction of conservation agriculture as a no-till forage crop production will help livestock producers to have access to low-cost forage resources and thus improve the efficiency of livestock production in Uzbekistan, and perhaps in other Central Asian countries as well. This beneficial aspect of crop rotation with integration of livestock sector should be further investigated in the Aral Sea basin.
References:
1. Bot A. and Benites J. The importance of soil organic matter: the key to drought resistant soil, sustained food and production. FAO Soils Bulletin- 2005.- No. 80. URL:http://www.fao.org/docrep/009/ a0100e/a0100e00.htm
2. Suleymenov M. K., Akshalov K. A. Vzaimodeystviye sevooborota i urovnya agrotekhniki vozdelk vaniya polevk kh kul'tur // Nou-till i plodosmen-osnova agrarnoy politiki poddarzhki resursosberegayuûego zemledeliya dlya intensifikatsii ustoychivogo proizvodstva. Mezhdunarodnaya konferentsiya, 8-10iyulya 2009 goda.- Astana-Shortandy. 2009.- P. 252-258.
3. Kosutic S., Filipovic D., Gospodaric Z., Husnjak S., Kovacev I., Copec K. (Effects of different soil tillage systems on yield of maize, winter wheat and soybean on albic luvisol in north-west slavonia // Journal of Central European Agriculture 2005.- V. 6.- No. 3.- P. 241-248.
4. Liebman M., and Gallandt E. R. Many little hammers: Ecological management of crop-weed interactions // In Agricultural Ecology, L. E. Jackson, ed., 1997.- P. 291-343. San Diego, CA: Academic Press.
5. Lovett Doust L., Mac Kinnon A., and Lovett Doust J. Biology of Canadian weeds. 71. Oxalis stricta L., O. maizeiculata L., O. dillenii Jacq. ssp. dillenii and O. dillenii Jacq. ssp. filipes (Small) Eiten. // Canadian Journal of Plant Science 1985.- No. 65.- P. 691-709.
