پديد آورندگان :
نصراله زاده، صفر دانشگاه تبريز - گروه اكوفيزيولوژي گياهان زراعي , شيرخاني، علي سازمان تحقيقات، ترويج و آموزش كشاورزي - مركز تحقيقات و آموزش كشاورزي و منابع طبيعي استان كرمانشاه - بخش تحقيقات گياهان زراعي و باغي , زهتاب سلماسي، سعيد دانشگاه تبريز - گروه اكوفيزيولوژي گياهان زراعي , چوكان، رجب موسسه تحقيقات اصلاح و تهيه نهال و بذرف كرج
كليدواژه :
ازوتوباكتر , ذرت , كودهاي شيميايي , ورمي كمپوست و عملكرد
چكيده فارسي :
اين تحقيق باهدف مطالعه اثر ازتوباكتر و ورمي كمپوست به عنوان كودهاي زيستي و همچنين كودهاي شيميايي (NPK) بر عملكرد دانه و ويژگي هاي برگ ذرت به مدت دو سال (1392و1393) در ايستگاه تحقيقاتي اسلام‌آباد غرب، مركز تحقيقات و آموزش كشاورزي و منابع طبيعي استان كرمانشاه انجام شد. اين تحقيق به‌صورت آزمايش اسپليت پلات فاكتوريل در قالب طرح بلوكهاي كامل تصادفي با سه تكرار بود. تيمار مصرف ازتوباكتر در بلوكهاي اصلي در دو سطح (مصرف و عدم مصرف) و كودهاي شيميايي در سه سطح (صفر، 50 درصد و 100 درصد مقدار توصيه‌شده بر اساس آزمون خاك) و ورمي كمپوست در چهار سطح (صفر، 2، 4 و 6 تن در هكتار) در كرت‌هاي فرعي قرار گرفتند.آزمايش در دو مكان آبياري مطلوب و كم آبياري نجام شد. نتايج نشان داد تيمارهاي كودي در هردو شرايط آبياري عملكرد دانه، شاخص سطح برگ و شاخص سبزينگي ذرت را به شكل معني‌داري افزايش داده و همچنين با استفاده از شش تن در هكتار ورمي كمپوست، مي‌توان تا 50 درصد مصرف كودهاي شيميايي را كاهش داد به‌نحوي‌كه عملكرد دانه در تيمار مصرف توأم 6 تن در هكتار ورمي كمپوست با 50 درصد كود شيميايي به ترتيب 10/5 و 5/2 تن در هكتار در شرايط آبياري مطلوب و محدود بود، درحالي‌كه عملكرد در تيمار مصرف 100 كود شيميايي به ترتيب 10/1 و 4/8 تن در هكتار بود.
چكيده لاتين :
Introduction: Corn (Zea mays L.) is one of the main crops for poultry and livestock feed as well as human consumption in Iran. Despite the efforts made to increase corn output in Iran, the current production levels fail to meet the growing demand for the crop and consequently the country has become a major importer of corn. This is mainly due to water scarcity in the regions where corn is cultivated. Corn is considered to be a crop with high nutritional requirements. Therefore, grain yield formation in this plant is largely depended on the application of fertilizers. Although the excessive use of chemical fertilizers is always offered by the conventional agriculture as the quickest solution to compensate for the lack of nutrients in the soils and to produce higher yields, this approach has caused environmental pollution and ecological damages, resulting in increased production cost. The alternative approach would be the integration of the concepts and principles of agro-ecology into food production systems. In this context, utilizing soil microorganisms is essential for designing sustainable agricultural systems, which can ensure constant food supply. Biofertilizers as an indispensable component of sustainable agriculture are critically important contributors to the reduction or elimination of the usage of chemical fertilizers (Arrudaa et al., 2013). The combined use of organic and chemical fertilizers is suggested as the best option for corn cultivation where the inclusion of compost, Azotobacter and green fertilizer in the cropping system can produce higher corn yields. (Kalhapure et al., 2013). Under water-limited conditions, the use of vermicomposts can ameliorate the deleterious effects of the stress on crops (Gholipoor et al., 2014). Moreover, it may increase soil water retention capability and enhance plant tolerance to drought stress via producing humic acid. The objective of this work was to determine the effects of biofertilizers and chemical fertilizers on yield and yield components of corn under full and deficit irrigation conditions in the western region of Iran. Also the study pursued the aim of finding the best biological treatments that could be applied to corn production systems to obtain higher yields while keeping the environment safe and clean. Materials and Methods: Field experiments were conducted for two cropping seasons (2014 – 2015) at Agricultural and Natural Resources Research Centre in Kermanshah, Iran. The effects of vermicompost and Azotobacter as a biofertilizers along with chemical fertilizers on corn yield performance under two different watering conditions (full and deficit irrigation) were investigated in two sites. The sites, which were 10m apart, were allocated to full irrigation or deficit irrigation (65% of the crop optimum water requirement). The experimental layout at each site was a three-factor factorial split plot in a randomized complete block design with three replications. The main plots were comprised of two levels of Azotobacter treatment (non-inoculation and inoculation), four rates of vermicompost (0, 2, 4 and 6 ton/ha). The subplots consisted of chemical fertilizers including N, P, K (0, 50% and 100%), which were recommended based on soil test results. Deficit irrigation treatment at the relevant site was applied in the middle phase of growth stage (approximately V6). Single cross corn cultivar (KSC704), which is commercially grown in the region and comprises 80% of the total corn cultivated area in Kermanshah province, was selected for the study. Observations on leaf area index (LAI), normalized difference vegetation index (NDVI), chlorophyll content and grain yield were recorded. The statistical variance analysis of the data was performed using ANOVA and means were compared by least significant difference (LSD). SAS software package was used for the statistical computation and the graphs were drawn by MS Excel. Results and Discussion: The results showed that corn grain yield, LAI, leaf chlorophyll content and NDVI were significantly affected by the irrigation treatments .However ,Azotobacter had no significant effect on the traits .All the investigated parameters were decreased by deficit irrigation .Vermicompost and chemical fertilizer increased the grain yield ,LAI ,leaf chlorophyll content and NDVI under both full and deficit irrigation conditions. The addition of vermicompost at rates of 4 ,2 and 6 ton/ha consistently and significantly increased grain yield in both irrigation conditions .The simultaneous application of 6 ton/ha of vermicompost and 50% of the recommended chemical fertilizers under full and deficit irrigation conditions produced 10.3 and 5.2 ton/ha of grain yield ,respectively ,which did not significantly differ from when 100% of the recommended fertilizers was used alone .The values for the latter were 10.2 and 4.7 ton/ha of grain yield under full and deficit irrigation treatments ,respectively .This indicates that it is possible to decrease the application of chemical fertilizers by % 50 with no negative impact on yield .Similarly ,Laekemariam and Gidago )2012( suggested that the integrated used of compost at 5 ton/ha along with chemical fertilizers resulted in better corn yields. The highest values of NDVI were obtained with 100 and % 50 application of fertilizers under full irrigation treatment .The increasing rates of vermicompost raised NAVI in both irrigation regimes but the extent of the increase was less than that of the fertilizers .It seems that the role of nitrogen in chlorophyll structure is the reason why fertilizers were more effective in increasing NAVI than vermicompost, Conclusion: Although in our experiment vermicompost and Azotobacter were not individually able to provide all the nutritional requirements of the corn ,the results showed that the amendment of 6 ton/ha vermicompost in soil together with 50% of NPK fertilizers were adequate to meet the corn nutrient needs .This indicated that corn grain yield did not decline when the consumption of chemical fertilizers was reduced from 100% to 50% because the presence of vermicompost at sufficient rates in rhizosphere compensated for the decreased fertilizer application .This can have positive implications for the environmental safety and soil health .Also ,the results showed that under the deficit irrigation ,vermicompost and Azotobacter were able to increase corn grain yield.
