• Authors:
    • Drinkwater, L. E.
    • Schipanski, M. E.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 90
  • Issue: 1
  • Year: 2011
  • Summary: The incorporation of legume cover crops into annual grain rotations remains limited, despite extensive evidence that they can reduce negative environmental impacts of agroecosystems while maintaining crop yields. Diversified grain rotations that include a winter cereal have a unique niche for interseeding cover crops. To understand how management-driven soil fertility differences and inter-seeding with grains influenced red clover (Trifolium pratense) N(2) fixation, we estimated biological N(2) fixation (BNF) in 2006 and 2007, using the (15)N natural abundance method across 15 farm fields characterized based on the reliance on BNF derived N inputs as a fraction of total N inputs. Plant treatments included winter grain with and without interseeded red clover, monoculture clover, monoculture orchardgrass (Dactylis glomerata), and clover-orchardgrass mixtures. Fields with a history of legume-based management had larger labile soil nitrogen pools and lower soil P levels. Orchardgrass biomass was positively correlated with the management-induced N fertility gradient, but we did not detect any relationship between soil N availability and clover N(2) fixation. Interseeding clover with a winter cereal did not alter winter grain yield, however, clover production was lower during the establishment year when interseeded with taller winter grain varieties, most likely due to competition for light. Interseeding clover increased the % N from fixation relative to the monoculture clover (72% vs. 63%, respectively) and the average total N(2) fixed at the end of the first growing season (57 vs. 47 kg N ha(-1), respectively). Similar principles could be applied to develop more cash crop-cover crop complementary pairings that provide both an annual grain harvest and legume cover crop benefits.
  • Authors:
    • Yano, K.
    • Araki, H.
    • Sekiya, N.
  • Source: Plant and Soil
  • Volume: 341
  • Issue: 1/2
  • Year: 2011
  • Summary: When a plant encounters spatially heterogeneous soil moisture within its root system, usually drier surface and moister subsurface soils, water can move between these layers through the root system, a plant process known as hydraulic lift or redistribution. The water thus transferred is available not only for the plant itself but also for its neighbors. We examined application of this process as a possible biological irrigation tool. As 'donors', we used perennial forage plants with their shoots removed to minimize the effect of light-interception by them on the 'receiver' plants growing alongside them. In a horizontally split-root experiment, where an upper container was filled with sand and a lower one with water, superior donor species could maintain the upper sand in a fully hydrated condition for several weeks, increasing stomatal conductance in the receivers. The effects were also confirmed in a water-limited agricultural field, as significant differences were found in canopy temperature and yield in neighboring crop plants in the presence or absence of donor root systems. These results suggest that deep-rooting associate plants with their shoots removed function as an irrigation tool and improve crop production in water-scarce environments.
  • Authors:
    • Miah, M. N. A.
    • Paul, G. C.
    • Siddique, M. A. B.
    • Amanullah, A. S. M.
  • Source: Pakistan Sugar Journal
  • Volume: 26
  • Issue: 3
  • Year: 2011
  • Summary: An experiment was conducted at Regional Sugarcane Research Station (RSRS). Thakurgaon during 2005-06 and 2006-07 cropping seasons to asses effects of different levels of irrigation and split application of N-K fertilizers in sugarcane (var. Isd 36) intercropped with potato (var. Diamond). The intercrop, potato received recommended fertilizer as usual. Application of Urea and Potash (N-K fertilizers) in two splits (B 1) produced highest number of tiller, millable cane and also highest yield in both levels of irrigation in both years. Though the difference was not significant over B 2 and B 3. But irrigation level A 1 (Six light irrigation with 65 mm effective rainfall) had significant difference over A 2 (five comparatively deep irrigation with same effective rainfall). Highest number of tiller (215.3*10 3 ha -1), millable cane (114.7*10 3 ha -1) and cane yield (109.9 t ha -1) were produced by the treatment B 1 under A 1 level of irrigation in the crop year 2006-07. Hence split application of N-K fertilizers with two equal splits applied at plantation and at 145 days after plantation and also light irrigation, 6 to 7 number with total amount of 460-500 mm including effective rainfall may be preferred for loamy and sandy loam soils.
  • Authors:
    • Naranjani, L.
    • Shahrajabian, M. H.
    • Soleymani, A.
  • Source: Journal of Food, Agriculture and Environment (JFAE)
  • Volume: 9
  • Issue: 1
  • Year: 2011
  • Summary: Population growth and the consequent pressure on land resources and frequent crop failures have led to greater land use as well as intercropping systems. In order to investigate the changes of ash percentage, important elements and solar radiation absorption of three cultivars of berseem clover as cover crops intercropped with forage corn in different levels of nitrogen starter fertilizer, an experiment was conducted in 2010, at Research Farm, Faculty of Agriculture, Islamic Azad University, Khorasgan Branch (Isfahan). A factorial layout within randomized complete block design with 3 replications was used. Cultivars were Karaj, Sacromont and Multicut, and nitrogen levels included 0, 40 and 60 kg/ha. The nitrogen fertilizer was provided from urea source (46% pure N). Cultivar had significant effect on ash percentage and solar radiation absorption. The effect of nitrogen also was significant on ash percentage, Fe content, Mn content and solar radiation absorption. Ash percentage, Fe content, solar radiation absorption and light transmission were significantly influenced by interaction between cultivar and nitrogen. The highest ash percentage, Fe and Zn content were related to Sacromont. The maximum Mn content, Cu content and light transmission were obtained by Multicut. The maximum solar radiation absorption was related to Karaj. The nutritive value of berseem clover was influenced by changes in different levels of nitrogen starter fertilizer. The highest ash percentage, Mn content, Cu content and light transmission was obtained by application of 40 kg N/ha. The maximum Zn content was related to application of 60 kg N/ha. Control treatment had the maximum Fe content and solar radiation absorption.
  • Authors:
    • Sediyama, G. C.
    • Moura, M. S. B. de
    • Souza, L. S. B. de
    • Silva, T. G. F. da
  • Source: Bragantia
  • Volume: 70
  • Issue: 3
  • Year: 2011
  • Summary: This study aimed to analyze the productivity, the water use efficiency, and the economical viability for corn and cowpea crops on single and intercropping systems in the Brazilian semiarid region. The experiment was carried out at Petrolina, State of Pernambuco. The crops, in different planting systems (single and intercropping), underwent the five blades of irrigation, applied at the flowering stage of cowpea to 40 days after sowing. Combining the settings of cultivation system and the different depths of irrigation, crops of maize and cowpea were subjected to 15 different treatments. To evaluate the performance of crops in the different treatments indicators that consider the production response of crops and the performance of the application of water in the production system were used. The grain yield responses of maize and cowpea to the soil water content were reduced in intercropped plantations, in relation to single cropping. Even so, in economic terms, the adoption of maize-cowpea proved to be more advantageous in all treatments.
  • Authors:
    • Thankamani, C. K.
    • Ashokan, P. K.
  • Source: Journal of Medicinal and Aromatic Plant Sciences
  • Volume: 33
  • Issue: 3
  • Year: 2011
  • Summary: An investigation on effect of different drip irrigation levels on growth, yield, nutrient uptake and dry matter partitioning of bush pepper grown in coconut garden was carried out Six drip irrigation schedules were compared with daily pot irrigation at the rate of 10 l per plant (control). The treatment consists seven, drip irrigation 2 liters per day (October-May), drip irrigation 4 liters per day (October-May), drip irrigation 8 liters per day (October-May), drip irrigation 12 liters per day (October-May), drip irrigation 16 liters per day (October-May), drip irrigation 16 liters per day (October-March) and control. Among the treatments highest yield was recorded by the treatment drip irrigation 8 liters per day (October-May). The total yield and dry matter production was lesser at lower levels of drip irrigation. Dry weight of stem, leaves and total dry matter production were higher for the treatments drip 8, 12,16 l/plant from October-May compared to pot irrigation. Uptake of nutrients were significantly influenced by drip irrigation levels and maximum uptake was recorded by the treatment drip irrigation 8 l/day followed by the treatment 161 drip (October-May).
  • Authors:
    • Abraham, T.
    • Thenua, O. V. S.
    • Sharma, U. C.
  • Source: INDIAN JOURNAL OF AGRICULTURAL SCIENCES
  • Volume: 81
  • Issue: 8
  • Year: 2011
  • Summary: The performance of sole Indian mustard, sole chickpea, and chickpea + Indian mustard (4:1) intercropping as affected by irrigation (irrigation at the pre-flowering stage, pod formation stage, or pre-flowering stage and pod formation stage of chickpea) and NPS rate (20:40:10 or 40:60:20 kg/ha, or the recommended 20:60:20 kg/ha) was studied in Bulandshar, Uttar Pradesh, India, during the rabi seasons of 2005-06 and 2006-07. In 2005-06, chickpea + Indian mustard exhibited greater dry matter accumulation than the other cropping systems; in 2005-06, the variation among the cropping systems was not significant. Irrigation twice on the first year and irrigation once on the second year resulted in greater dry matter accumulation. Among the fertilizer treatments, the recommended NPS rates registered the greatest dry matter accumulation. Sole Indian mustard exhibited the greatest N, P and S extraction. Irrigation at the pod filling stage and irrigation at the pre-flowering and pod formation stages resulted in the greatest N, P and S uptake. The sole Indian mustard had a higher yield than the intercropped Indian mustard. In general, irrigation at the pod filling stage enhanced the yield by 12% compared to the other irrigation regimes. The recommended fertilizer rates also gave the highest seed yield. The highest chickpea equivalent yields were obtained with intercropping, irrigation twice, and application of the recommended fertilizer rates. Chickpea + Indian mustard intercropping recorded the highest net return and cost:benefit ratio.
  • Authors:
    • Xu, W. L.
    • Feng, Y. Z.
    • Jang, Y. L.
    • Rao, X. J.
    • Wang, Z. G.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 48
  • Issue: 12
  • Year: 2011
  • Summary: Objective: The purpose of this project is to study the effects of different irrigation models of jujube-cotton intercropping in ecological areas on the temperature and humidity and determine the ecological result of different irrigation models to the environment in order to provide some scientific basis for optimum water-saving irrigation model for jujube-cotton intercropping. Method: Three EL-USB automatic measuring system of temperature and humidity was established in the different positions in treatment 1 - jujube garden, treatment 2 - double water pipes in one line, treatment 3 - spray, treatment 4 - ditch irrigation, treatment 5 - cotton, EL-USB automatic measuring system of temperature and humidity of different distances from tree row to be monitored for 3 days in a row. Result: Effects of east-to-west jujube row on micro-ecological areas temperature are: the south of Jujube > the north of Jujube > Jujube row, and humidity: jujube row > The north of Jujube > The south of jujube; There was a negative linear correlation between humidity and temperature. Effects of different irrigation models on micro-ecological areas temperature of Jujube-cotton intercropping are: treatment 5 > treatment 1 > treatment 4 > treatment 3 > treatment 2, and humidity: treatment 2 > treatment 3 > treatment 4 > treatment 1 > treatment 5. Conclusion: Results showed that the crown shading of a east-to-west jujube row affected micro-ecological area temperature and humidity differently with different directions from tree row. Generally, temperature is the south of Jujube > the north of jujube > jujube row. There was a negative linear correlation between humidity and temperature. The temperature of jujube-cotton intercropping is lower than that of the single cotton model, but the humidity is higher. The treatment of spray and the treatment of double water pipes influence temperature and humidity greatly, which was advantageous to increase the jujube fruit setting rate.
  • Authors:
    • Chai, Q.
    • Huang, G. B.
    • Yang, C. H.
    • Luo, Z. X.
  • Source: Field Crops Research
  • Volume: 124
  • Issue: 3
  • Year: 2011
  • Summary: A field experiment was carried out to investigate the effects of alternate irrigation (AI) on the yield, water use and water use efficiency (WUE) of wheat (Triticum aestivum L.)/maize (Zea mays L.) intercropping system in an oasis region of northwest China in 2006-2008. Three planting patterns, i.e., sole wheat, sole maize and wheat/maize intercropping. Three irrigation levels were applied for each treatment during 3 years. Results showed that land use efficiency of wheat and maize was significantly enhanced by intercropping system; land equivalent ratio (LER) of wheat/maize intercropping system in different treatments was all greater than 1.0. Moreover, significant difference in grain yield was observed between intercropping treatment and sole cropping treatment, in which the yield of intercropped wheat was 55.37-74.88% of sole wheat, and intercropped maize was 66.63-78.87% of sole maize. Wheat/maize intercropping treatments increased water use by 1.8-16.4% than half of the total water use of sole-cropping wheat and maize. Compared to sole cropping wheat treatments, wheat/maize intercropping with alternate irrigation significantly improved water use efficiency (WUE) by 30.5-57.7%, 55.5-71.4% and 12.0-19.8%, and increased by 32.7-37.8%, 9.5-15.8% and 4.0-20.8% than sole cropping maize treatments in 2006-2008, respectively. Our results suggest that AI should be a useful water-saving irrigation method on wheat/maize intercropping in arid oasis field where intercropping planting is decreased because of limited water resource.
  • Authors:
    • Ouyang, W.
    • Wang, Y. H.
    • Wang, X.
    • Hao, F. H.
    • Zhang, X.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 27
  • Issue: 6
  • Year: 2011
  • Summary: To assess the phosphorus loss under different crops cultivations in farmland, soil samplings were taken in four typical crop types' fields in five layers of 0-100 cm. Based on the isothermal methane-adsorbing experiments, SPSS software was applied to analyze the results statistically. The phosphorus loss potential was evaluated and the influence factors were discussed in this paper. The results revealed that the sorption characteristics of all the soil samples in the study area could be described by Langmiur and Freundich equations, and the Langmiur equation fit better. The soil in wheat field showed better sorption of phosphorus than that of other crops. The soil samples of intercropping field demonstrated poor sorption capacity. The phosphorus sorption of the top soil in the different crop fields showed few variations. Compared with the phosphorus sorption of the deeper layers, the top soil was prone to lose along with farmland drainage except in the intercropping field, where the phosphorus loss with seepage vertically into groundwater was the preferential way. Phosphorus sorption index (PSI) was another effective parameter to assess the phosphorus loss potential except for the theoretically maximum sorption capacity Qm and the equilibrium phosphorus concentration at zero sorption (EPC 0). The conclusions of this paper can provide scientific references for appropriate scheduling on efficient fertilization, irrigation, and non-point source pollution control.