جستجوی مقالات مرتبط با کلیدواژه "مجموع ارزش نسبی" در نشریات گروه "زراعت"

Today, agroforestry production systems as viable strategy for sustainable agriculture, is appreciated by both researchers and farmers, as it increases the efficiency of natural resources uses and may enhance the combined production of wood and crop products and hence income of the rural communities. In order to investigate the benefits of the agroforestry system of Euramerican poplar (Populus euramericana clone of 92/40) and alfalfa fodder plant (Medicago sativa), an experiment was carried out in the form of Randomized Complete Block Design (RCBD) with three replications at the Alborz Research Station in the south of Karaj, Iran. The treatments included poplar pure culture, alfalfa pure culture, and poplar-alfalfa mixed culture. Alfalfa plants were planted between the rows of poplar (Populus euramericana clone of 92/40) which were planted in March 2015 at a distance of 3 × 4 m, in late autumn 2016. The height and diameter at breast height (DBH) of the poplar trees were measured at the end of each growing season for three consecutive years, and then the annual increment in growth of height, diameter and stem volume (m3/ha) were calculated and evaluated using the T-Test. The plant height and dry weight of alfalfa were measured for the three years and its total annual fodder dry mass yield was obtained. Competitive and economic evaluation of each of the pure and agroforestry cultivations was done based on the indices of land equality ratio (LER), relative value total (RVT) and advantage index (IA). In 2019 and 2020, there was a statistically significant difference in the DBH and stem volume in pure and agroforestry cultivations, indicating the highest values for both parameters in pure poplar culture. In 2018, the highest alfalfa fodder dry mass yield was obtained in agroforestry cultivation with 11320 kg ha-1 but the highest alfalfa fodder dry mass in 2019 (with 10928 kg ha-1) belonged to its pure cultivation. In all the studied years, LER was greater than one and ranged from 1.27 to 2.39, with the three-year average being 1.78. The values for RVT in 2018, 2019, and 2020 were 1.6, 0.69 and 0.41 and those for IA were 6.53, 4, and 2.81, respectively. Therefore, adopting agroforestry by cultivation of poplar and alfalfa will enable the farmers to receive 160%, 69%, and 41% increases in income compared to the income from pure cultivation of poplar and alfalfa for the years 2018, 2019 and 2020, respectively.

Cereals with legume intercropping as one of the ways to increase yield per unit area are recommended. To investigate the effect of cutting off irrigation on yield, yield component and advantageous indices of barley intercropped with legumes, a field experiment was conducted as split plot in randomized complete blocks design with three replicates at College of Agriculture and Natural Resources of Darab, Shiraz University during 2014 growing season. Treatments were included two levels of irrigation regimes as main plot (full irrigation and cutting off irrigation at milk development stage) and cropping treatments consisted of monoculture of Nimroz tow-rowed barley, Zehak six-rowed barley, pea and faba bean and intercropping of Nimroz + pea, Nimroz + faba bean, Zehak + pea and Zehak + faba bean) with a ratio of 1:1 as sub plot. Results showed that under cutting off irrigation number of seeds/spike, harvest index, biological yield and grain yield of barley cultivars decreased 12.5%, 23.6%, 4.3% and 20%, respectively. Under cutting of irrigation at milk development stage, the highest grain yield was obtained in monocropping of Zehak (3470 kg/ha) and Nimroz (3300 kg/ha). After cutting off irrigation at milk development stage, the lowest canopy temperature (28 to 30 ºC) was observed in intercropping treatments. The highest land equivalent ratio (LER) of barley (0.57), legumes (0.83), and total (1.4) were obtained in intercropping of Zehak + pea. In both of the irrigation regimes, Zehak and Nimroz barley cultivars intercropped with faba bean had higher relative value total (RVT) compared to monoculture. In addition, Zehak barley cultivar due to higher grain yield, LER and RVT was better option in intercropping with legumes compared to Nimroz cultivar, under water stress.

In order to assess the effect of different fertilization systems on competitive and economic indices of fenugreek and black cumin intercropping, a factorial experiment was conducted based on randomized complete block design with three replications at Shahrekord University Research Farm in 2013. Sole cropping of fenugreek (F), Sole cropping of black cumin (B) and three intercropping ratios (B:F; 2:1, 1:1, and 1:2) were evaluated as the first factor and three sources of fertilizer consist of chemical fertilizer, broiler litter and integrated fertilizer (1:1) as the second factor. Results showed that fenugreek was dominant plant and had greater competitive inetensity than black cumin, but broiler litter application reduced the amount of competition. The competitive indices were markedly reduced under broiler litter application. The greatest value of land equivalent ratio (LER), relative crowding coefficient (K), actual yield loss (AYL), monetary advantage (MA) and intercropping advantage (IA) was observed for B:F (2:1) treatment under broiler litter application. Overall, the application of animal manures in sustainable agriculture will increase intercropping advantages compared to chemical fertilization system.

To investigate the effects of intercropping of basil (Ocimum basiilicum L.) and cowpea (Vigna unguiculata L.), different levels of nitrogen fertilizers on basil and cowpea yield, an experiment was carried out during 2010 and 2011. Experimental factor were included weed treatment (weeding and unweeding), three levels of nitrogen fertilizer (0, 50 and 100 kg ha-1), different planting ratio, (P1: sole cropping of cowpea, P2: 100% cowpea+ 25% basil, P3: 100% cowpea+ 50 % basil, P4: 100% cowpea+ 25% basil, P5: sole cropping of basil). Results showed that the maximum yield of basil (430.37 kg ha-1) and cowpea (685.16 kg ha-1) recorded in 100 and 50 mixture with using of 100 and 50 kg ha-1 nitrogen fertilizer in weed control condition, respectively. In unweeding conditions, however, the maximum yield of basil (138.95 kg ha-1) was obtained in both 100 and 25 planting ratio plus 100 kg ha-1 nitrogen fertilizer. Also the highest intercropping advantage (LA= 1.74) belonged to 100 and 25 planting ratio along with 100 kg ha-1 nitrogen fertilizer and weeding. Land equivalent ratio (LER=1.43) in 100 and 50 mixture with 50 kg ha-1 nitrogen fertilizer and weeding was more than sole cropping. Also the highest relative value total (RVT= 1.88) was observed in 100 and 50 planting ratio plus 100 kg ha-1 nitrogen with weeding condition. In conclusion, cultivation of cowpea as a cover crop in basil/cowpea intercropping system could and improve nitrogen status and suppressed weed population and biomass as compared to basil sole cropping.

In order to study of use advantage in the intercropping system fennel (Foeniculum vulgare Mill) and fenugreek (Trigonella foenum-graecum L) in different ratios of intercropping and sole cropping, an experiment with use replacement and additive intercropping based on randomized complete block design with three replications was conducted at the Research Station of Faculty of Agriculture, University of Zanjan, Iran, during growing season 2012. Treatments included additive intercropping in three levels (100 percent fennel + 33, 66 and 100 percent fenugreek), replacement intercropping in six levels (1:1, 1:2, 2:1, 2:2, 1:3, 3:1), Sole fennel and Sole fenugreek. Results showed that the highest grain yield of Fenugreek was obtained in pure stand of Fenugreek and the lowest of mentioned trait was obtained in the 75 percent fennel + 25 percent fenugreek (3:1) replacement series. Also the highest and the lowest fennel grain yield were obtained in 100 percent fennel + 33 percent fenugreek additive series and 25 percent fennel + 75 percent fenugreek (1:3) replacement series respectively. yield of essential oil at 100 percent fennel + 33 percent fenugreek additive series were higher compared with sole cropping. The highest Land Equivalent and Relative Value Total obtained from 100 percent fennel + 33 percent fenugreek additive series. The highest Actual Yield Loos or gain (AYL) and intercropping advantage (IA) obtained from 25 percent fennel + 75 percent fenugreek (1:3) replacement series. Aggressively index revealed that in most sowing ratios fennel was dominant and fenugreek was defeated.