Showing 3 results for Fertigation
A. Karimi, M. Mazardalan, M. Homaeia, A. M. Liaghat, F. Raissi,
Volume 11, Issue 40 (7-2007)
Abstract
In Iran, fertilizers are mainly applied directly to soil. In such conditions, the yield and fertilizer use efficiency are usually low. The simultaneous application of fertilizers and irrigation water (fertigation) is an appropriate alternative to increase the efficiency of applied water and fertilizers. The objective of this study was to investigate the effect of various irrigation and fertilizer amounts on efficiency of applied fertilizers when used as fertigation in a Tape irrigation system. A field experiment was carried out with sunflower as a completely randomized design with 20 treatments and 3 replicates. The fertilizers were applied by fertigation. Four levels of the water (60, 80, 100 and 120% treatments I1 to I4) and five rates of the recommended fertilizers (0, 60, 80, 100, and 120% treatments F0 to F4) were applied.The recommended amounts consisted of 400 kg CO(NH2)2, 50 kg KCl, 30 kg FeSO4, 30 kg MnSO4, 50 kg ZnSO4, 30 kg CuSO4, and 30 kg H3BO3 per ha. Tape irrigation was used for every treatment. The results indicated that in fertigation method, there were significant differences ( P≥0.01) in fertilizer use efficiency (FUE) for the total dry matter and grain yield between treatments. The results showed that by increasing applied water, fertilizer use efficiency was increased and affected by fertilizers treatments. Thus due to higher availability of nutrients, fertilizer use efficiency increased. was Fertilizer use efficiency also decreased by increasing fertilizer rate. The results also demonstrated there were significant differences in all the treatments. The results showed that fertilizer use efficiency of K is higher than N and N is higher than P.
H.a Alizadeh , F Abbasi , A Liaghat ,
Volume 14, Issue 51 (4-2010)
Abstract
The application of N fertilizers with surface irrigation stream (surface N fertigation( is a key approach for fertilizer management. The main objective of this study was to investigate furrow fertigation management effects on distribution uniformity and runoff losses of nitrate in field scale. A field corn experiment was carried out with a complete randomized block design having 12 experiments. The field experiments were carried out in free draining furrows having 165 m length and 0.006 m/m slope in Karaj. Required urea fertilizer was applied in four stages: before planting, in seven leaves stage, shooting stage and earring stage. The first stage was accomplished by traditional method and other stages were applied with irrigation water (fertigation). Fertigation timing was respectively 60, 35, and 20 min in the three fertigation stages. Results showed that distribution uniformity of water and fertilizer of low half (DULH) provided high values for all experiments. DULH ranged between 88.0 to 99.0% and 89.7 to 96.0%, respectively for water and fertilizer. Also, distribution uniformity of low quarter (DULQ) ranged between 86.0 to 98.2% and 85.7 to 91.5%, respectively for water and fertilizer. Nitrate losses through surface runoff ranged between 5.7 to 42.0%. Duncan test results for comparison between different experiments showed that there was significant difference (p=0.95) between fertilizer losses at the level of fertilizer injection time of 60 and 35 minutes, but there was no significant difference between levels of 35 and 20 minutes.
H. Shekofteh, M. Afyuni, M. A. Hajabbasi, H. Nezamabadi-Pour, F. Abbasi, F. Sheikholeslam,
Volume 18, Issue 70 (3-2015)
Abstract
The conventional application of nitrogen fertilizers via irrigation is likely to be responsible for the increased nitrate concentration in groundwater of areas dominated by irrigated agriculture. This requires appropriate water and nutrient management to minimize groundwater pollution and to maximize nutrient use efficiency and production. To fulfill these requirements, drip fertigation is an important alternative. Design and operation of drip fertigation system requires understanding of nutrient leaching behavior in cases of shallow rooted crops such as potatoes, which cannot extract nutrient from lower soil depth. This study deals with neuro-fuzzy modeling of nitrate leaching from a potato field under a drip fertigation system. In the first part of the study, a two-dimensional solute transport model (HYDRUS-2D) was used to simulate nitrate leaching from a sandy soil with varying emitter discharge rates and various amounts of fertilizer. The results from the modeling were used to train and validate an adaptive network-based fuzzy inference system (ANFIS) in order to estimate nitrate leaching. Radii of clusters in ANFIS were tuned and optimized by genetic algorithm. Relative mean absolute error percentage (RMAEP) and correlation coefficient (R) between measured and obtained data from HYDRUS were 0.64 and 0.99, respectively. Results showed that ANFIS can accurately predict nitrate leaching in soil. The proposed methodology can be used to reduce the effect of uncertainties in relation to field data.
