Application of liquid micro compound fertilizer to increase yield and agronomic feasibility of sweet corn

The objective of the research was to determine the appropriate dosage of liquid micro-compound fertilizer on crop yield and agronomic feasibility of sweet corn. This research was carried out in Mojokerto District on DS 2021, using of plot 4 m x 5 m with 10 treatments, using RBD, repeated 4 times. The treatment of liquid micro compound fertilizer (LMC), namely A. 0 kg.ha−1 Urea + 0 kg.ha−1 ZA + 0 kg.ha−1 NPK + 0 l.ha−1 LMC (control), B. 200 kg/ha Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 0 l.ha−1 LMC (standard), C. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 5 l.ha−1 LMC, D. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 10 l.ha−1 LMC, E. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK+15 l.ha−1 LMC, F. 200 kg.ha−1 Urea + 100 kg.ha−1 ZA + 275 kg.ha−1 NPK + 20 l.ha−1 LMC, G. 150 kg.ha−1 Urea + 75 kg.ha−1 ZA + 200 kg.ha−1 NPK+5 l.ha−1 LMC, H. 150 kg.ha−1 Urea+75 kg.ha−1 ZA+200 kg.ha−1 NPK+10 l.ha−1 LMC, I. 150 kg.ha−1 Urea + 75 kg.ha−1 ZA + 200 kg.ha−1 NPK + 15 l.ha−1 LMC, and J. 150 kg.ha−1 Urea + 75 kg.ha−1 ZA + 200 kg.ha−1 NPK + 20 l.ha−1 LMC. The results showed the application of 5 l.ha−1 LMC fertilizer combined with Urea 200 kg.ha−1 + ZA 100 kg.ha−1 + NPK 275 kg.ha−1 (treatment C) obtained the highest cob cornhusks weight of 13.66 t.ha−1 with RAE 120% and R/C ratio 3.13.


I. Introduction
Fertilization is an influential factor in increasing the growth and productivity of sweet corn plants.Fertilization in a balanced manner with location-specific recommended doses will increase the productivity and quality of crop yields [1].Nutrient requirements for sweet corn plants can be in the form of macro nutrients and micro nutrients to obtain optimal cob yields.So far, the nutrient requirements for sweet corn plants have only been met by applying fertilizers containing macronutrients, especially N fertilizers.The continuous use of N nutrients without the provision of other nutrients can cause a decrease in soil fertility [2][3][4], and affects the decrease in plant productivity.Excess fertilizer application is not only a waste of funds, it also disrupts the balance of nutrient elements in the soil and pollutes the environment [5][6][7][8], while applying too much fertilizer little can not provide an optimal level of rice production.Fertilization that only uses elemental N can reduce the content of organic-C, available-P and CEC of the soil, causing an imbalance of nutrients in the soil.
Rational fertilization is an effort to increase production cost efficiency and optimize the increase in corn production.If the application of inorganic fertilizers through the soil is not timely and the dosage is not correct, it can reduce fertilization efficiency [9] as well as disrupt the balance of nutrients in the soil.The process of fertilization in plants will experience loss of N-inorganic elements mainly due to denitrification, volatilization, leaching and carried away by surface runoff [10].In addition to macronutrient fertilizers, it is necessary to apply micro-nutrient fertilizers, especially for paddy fields which are cultivated intensively in a specific soil environment.Efforts to improve the efficiency of fertilizer application include the dose of fertilizer application, the method of application and the form of fertilizer, including the dose of fertilizer application, the time of application of fertilizer, the method of application and the form of fertilizer used appropriately [11].If the application of fertilizer through the soil is not timely, the dosage and its management can reduce the efficiency of fertilization and disrupt the balance of nutrients in the soil [12].Application of liquid micro-compound fertilizer given by spray to plants helps increase crop production and quality, and reduces the use of macro-inorganic fertilizers [13,14].Thus the level of absorption of nutrients and water by sweet corn plants reaches the optimum limit to be used for cell division, elongation and differentiation.Micro-nutrients are needed in small amounts, but micro-nutrients are used as catalysts, which means that micro-nutrients can accelerate the process of chemical compounds in plants.Fauziah et al. (2018) stated that the provision of micro-nutrients through the leaves is considered more effective because the micro-nutrients provided will be more easily absorbed by plants through the stomata found on the leaves [15].Zn deficiency has been reported to occur in various plants in Andisols which consequently can reduce plant productivity.Although it is needed only in small amounts (micronutrients), Zn has an important role in the survival and production of agriculture [16].Likewise other micro nutrients such as Cu which is absorbed by plants in the form of Cu ++ is very much needed in the formation of enzymes, namely Ascorbic acid oxydase, Lacosa, Butirid coenzim A. dehydrosenam and plays an important role in the formation of green leaves (chlorophyll) [17].The objective of the research was to determine the appropriate dosage of liquid micro-compound fertilizer on crop yield and agronomic feasibility of sweet corn.

Materials and methods
This research was conducted in the lowland of the Experimental Garden of Mojosari, Mojosari Subdistrict, Mojokerto District during the dry season 2021, using a 4 m x 5 m experimental plot with 10 treatments arranged based on a Randomized Block Design repeated 4 times, analyzed by ANOVA followed by Duncan's Significant Difference Test (DMRT 5%) [18].The treatment was a combination of macro-inorganic fertilization doses with "Green Tonvit" liquid micro compound (LMC) fertilizer (Table 1).The sweet corn seeds used were the Talenta variety which were planted in spacing of 70 cm x 20 cm, drilled planting with 1 seed per hole.Liquid micro compound fertilization containing 1.67% Zn and 0.80% Cu, applied at a concentration of 3-5 ml.l -1 water, sprayed on the plants 2 weeks after planting (MST) with an interval of every 10 days, stopped at the time of flowering and Continue until it fills the cobs (5 times spraying).Doses of liquid macro-inorganic and micro-liquid fertilizers were given according to the treatment.NPK fertilizer with 1/2 dose and 1/3 dose of Urea and ZA fertilizer was given at the age of 7 days after planting (DAP).Half dose of NPK fertilizer and 1/3 dose of Urea or ZA fertilizer is given at 25 DAP, and the remaining 1/3 dose of Urea and ZA fertilizer is given at 35 DAP.
Plant observation variables included: soil nutrient status before the study, plant height at 14, 28, 42, 56, and 70 DAP, number of leaves per plant at 14, 28, 42, 56, and 70 DAP, stem diameter at 28, 42, 56, and 70 DAP, dry biomass weight per plant 14, 28, 42, 56, and 70 DAP, length and cob diameter, weight per cob of husk, ratio of cob to cobs, ratio of seeds to cob, and cob weight (t.ha -1 ).Assessment of technical/agronomical effectiveness is carried out by calculating the value of Relative Agronomic Effectiveness (RAE).RAE is the ratio between the increase in yield due to the use of fertilizer and the increase in yield with the use of standard fertilizer multiplied by 100 [19], the formula is: Financial analysis to determine the feasibility of shallot farming using the R/C ratio (Soekartawi, 2002).Mathematically, the feasibility of shallot farming by calculating the R/C ratio is as follows: where, R/C = Revenue and cost ratio NPT = Total production value (IDR/ha) BT = Total cost value (IDR/ha) Plant growth analysis includes: -Leaf Area (LA): length x leaf width x constant (0.75), is the area of the number of leaves per plant, namely: -Leaf Area Index (LAI): the ratio between the total leaf area and the land area, describing the ability of plants to absorb solar radiation for the process of photosynthesis, obtained by measuring all leaves that are perfectly open, namely: -Crop Growth Rate (CGR ): the average rate of increase in dry weight of total plant biomass per unit land area per unit time during a certain period, namely: Description : w1,2 = plant dry weight at time t1,2 p = land area for one plant/clump t1,2 = initial observation time in a certain period, the next period A1,2 = leaf area at time t1,2

Plant growth and yield
The growth and yield of sweet corn plants are influenced by genetic, environmental and plant management factors.One of the important factors that affect the growth and yield of sweet corn is fertilization [20], both through the addition of macro elements and micro elements needed by sweet corn plants.Fertilization treatment on sweet corn plants can significantly affect plant height (Table 2).Differences in plant height increase significantly began to be seen consistently at the ages of 42 DAP, 56 DAP and 70 DAP.The highest plant height was found in the treatment of Urea 200 kg.ha - + ZA 100 kg.ha -1 + NPK 275 kg.ha -1 + LMC 5 l.ha -1 (Treatment C) which was significantly different from the treatment without fertilization (treatment A) and standard fertilization + 10 l.ha -1 LMC (treatment D).In accordance with the results of research by Ukonze et al. (2016) showed that differences in plant height, stem girth and leaf area of maize plants were significantly seen at the age of 56 days after planting (DAP) [21].The number of leaves per plant increased significantly since the plant was 28 DAP, 42 DAP, 56 DAP and 70 DAP due to fertilization treatment (Table 3).At the beginning of the growth of the sweet corn plant, namely the observation at 14 DAP did not show a significant difference in plant height, but in subsequent observations there was a significant difference in the number of leaves to the treatment without fertilization (treatment A).Fertilization treatment on sweet corn causes a significant difference in stem diameter in each plant observation (Table 4).Leaf area is affected by the development of the number of leaves per plant multiplied by the area per leaf.The increasing number of leaves per plant affects the addition of leaf area per plant (Table 5).At the beginning of growth, namely the observation at 14 DAP did not show a significant increase in leaf area and was strongly influenced by the development of the number of leaves per plant (Table 5).According to the results research by Aisyawati et al. (2022) that, the lowest leaf area per plant was found in the treatment without fertilization (treatment A), while between other fertilization treatments there was no significant difference [22].This shows that the land used is less fertile so it is very responsive to the application of fertilizer, although the variation in the increase in leaf area per plant is not significantly different between the doses of fertilization given to sweet corn plants.Leaf area index is the ratio of leaf area per plant to sweet corn planting area (Table 6).The leaf area index per plant was influenced by the development of leaf number and leaf area per plant, so that the growth (observation at 14 DAP) did not show a significant difference.The following observations showed that the treatment without fertilization (treatment A) produced the lowest leaf area index.Between fertilization treatments ( B, C, D, E, F, G, H, I, and J) there were variations in the increase in leaf area index per plant but each increase was not significantly different.The crop growth rate is the increase in plant dry weight per unit time (Table 7).At the beginning of growth, namely observation at 14 DAP and 42 DAP, the fertilization treatment did not show an increase in plant weight which could affect plant growth rate, while in subsequent observations (28 DAP and 42 DAP) there was a marked increase in plant growth rate.At 56 DAP, the 1253 (2023) 012023 IOP Publishing doi:10.1088/1755-1315/1253/1/0120237 plant growth rate increased sharply, then decreased again at 70 DAP.It is suspected that at this age it is a generative phase, including the development and filling of cobs formed optimally so that it affects the increase in plant dry weight.The absence of differences between fertilization treatments indicated that there was no difference in the increase in plant dry weight per unit area so that crop growth rates were not significantly different.Dry biomass weight per plant at 14 DAP observation showed no significant difference between fertilization treatments on sweet corn (Table 8).The lowest dry biomass weight per plant without fertilization (treatment A).However, in the fertilization treatment (treatments B, C, D, E, F, G, H, I, and J) there was no significant difference in dry biomass weight.The effect of fertilization on cob length, cob diameter, ratio of cobs to cobs of cornhusks and ratio of seeds to cobs showed significant differences, except for the number of cobs per plant (Table 9).No fertilizer application (treatment A) on sweet corn showed a significantly lower cob length and cob diameter, while the application of fertilizers at different doses did not show a significant difference to cob length and cob diameter.The ratio of cobs to cobs of cornhusks is around 72.24% -78.84%, the rest (21.16% -27.76%) is the weight of the husks, while the ratio of fresh seeds to cobs is around 59.61% -70.56%, the rest (29.44% -40.39%) is the weight of seedless cobs.The lowest cob to cob s of cornhusk ratio and seed to cob ratio were found in unfertilized sweet corn (treatment A).
The fertilization treatment on sweet corn caused a significant increase in the weight of the cobs cornhusk and affected the Relative Agronomic Effectiveness (RAE) (Table 10).Unfertilized sweet corn plants (treatment A) obtained a significantly lower cob cornhusks weight (3.84 t.ha -1 ) compared to other fertilization treatments.In line with the research results of Abror and Anwar (2017) that liquid compound fertilization at doses of 2 ml, 4 ml and 6 ml did not significantly affect of plant height, number of branches, number of leaves, number of fruits and fruit weight [23].Even though the cob cornhusks weight was not significantly different, the highest yield was found in Urea 200 kg.ha - + ZA 100 kg.ha -1 + NPK 275 kg.ha -1 + 5 l.ha -1 LMC (treatment C) of 13.66 t.ha -1 .Provision of micronutrients can meet the needs of plants to carry out the photosynthesis process properly so that more photosynthates are produced [24], thus affecting plant yields.Rozen et al. (2017) added that applying micronutrients can increase crop yields by 3.8 -15% [25].According to Bertham et al. (2022) that micronutrients play a role in plant growth, chlorophyll formation, and can improve plant health and productivity [26].
The increase in cob weight with fertilization treatment compared to standard fertilization treatment (treatment B), will affect the RAE value.With Urea 200 kg.ha - + ZA 100 kg.ha -1 + NPK 275 kg.ha -1 + LMC 5 l.ha -1 (treatment C) a weight of 13,663 kg.ha -1 cobs cornhusks was obtained which was higher than standard fertilization, namely Urea 200 kg.ha - + ZA 100 kg.ha -1 + NPK 275 kg.ha -1 (treatment B) so that after deducting the cobs cornhusks weight without fertilization (treatment A), an RAE of 120% or higher is obtained compared to the RAE of standard fertilization treatment (treatment B) with an RAE of 100 %.Thus the application of standard fertilizer Urea 200 kg.ha - + ZA 100 kg.ha -1 + NPK 275 kg.ha -1 requires 5 l.ha -1 LMC which is sprayed on sweet corn plants to increase cob cornhusks weight.Liquid micro compound fertilization containing 1.67% Zn needed for plant production and 0.80% Cu needed in the formation of green leaves (chlorophyll) in the photosynthesis process of sweet corn plants.

Conclusion
• Provision of standard fertilizer, namely Urea 200 kg.ha - + ZA 100 kg.ha -1 + NPK 275 kg.ha -1 required the addition of liquid micro compound fertilizer in plants to increase the weight of sweet corn cobs.• Applying 5 l.ha -1 of liquid micro compound fertilizer combined with Urea 200 kg.ha - + ZA 100 kg.ha -1 + NPK 275 kg.ha -1 (treatment C) obtained a sweet corn cob cornhusks weight of 13.66 t.ha - 1 with RAE 120% and R/C ratio 3.13.

Table 1 .
Treatment of liquid micronutrient fertilization on sweet corn plants, dry season 2021 at the Experimental Garden of Mojosari, Mojokerto.

Table 2 .
Plant height of sweet corn with liquid micro compound fertilization treatment in the dry season 2021 at the Experimental Garden of Mojosari-Mojokerto.
* DAP = Day After Planting Means in the same column followed by the different letters differ significantly under DMRT (α≤ 5%)

Table 3 .
Number of leaves per plant of sweet corn treated with liquid micro compound fertilization in the dry season 2021 at the Experimental Gardens of Mojosari-Mojokerto.

Table 4 .
Stem diameter of sweet corn plants with liquid micro compound fertilization treatment in the dry season 2021 at the Experimental Garden of Mojosari-Mojokerto.
* DAP = Day After Planting Means in the same column followed by the different letters differ significantly under DMRT (α≤ 5%)

Table 5 .
Leaf area per plant of sweet corn with liquid micro compound fertilization treatment in the dry season 2021 at the Experimental Garden of Mojosari-Mojokerto.

Table 6 .
Leaf Area Index (LAI) of sweet corn plants with liquid micro compound fertilization treatment in the dry season 2021 at the Experimental Garden of Mojosari-Mojokerto.
* DAP = Day After Planting Means in the same column followed by the different letters differ significantly under DMRT (α≤ 5%)

Table 7 .
Crop Growth Rate (CGR) of sweet corn with liquid micro compound fertilization treatment in the dry season 2021 at the Experimental Garden of Mojosari-Mojokerto.
* DAP = Day After Planting Means in the same column followed by the different letters differ significantly under DMRT (α≤ 5%)

Table 8 .
Dry biomass weight per plant of sweet corn with liquid micro-multiple fertilization treatment in the dry season 2021 at the Experimental Garden of Mojosari-Mojokerto.
* DAP = Day After Planting Means in the same column followed by the different letters differ significantly under DMRT (α≤ 5%)

Table 9 .
Cob length, cob diameter, ratio of cobs to cobs of cornhusks and ratio of seeds to cobs of sweet corn with liquid micro-compound fertilization treatment in the dry season 2021 at the Experimental Garden of Mojosari-Mojokerto.
* DAP = Day After Planting Means in the same column followed by the different letters differ significantly under DMRT (α≤ 5%)

Table 10 .
The weight of the cobs cornhusk and RAE value in micro-liquid compound fertilization treatment in the dry season 2021 at the Experimental Garden of Mojosari-Mojokerto.