Liquid organic fertilizer effectiveness test and the combination with chemical fertilizer on maize to increase yield in dry land

The aim of the research was to examine the effectiveness of Liquid Organic Fertilizer (LOF) combination with chemical fertilizer on maize to increase yield in dry land. The research was conducted from May to October 2018 in Kediri Regency. The research used a RBD with seven treatments and four replications, namely were: A = Control; B = RRCF; C = 6 L LOF ha-1; D = ¾ RRCF + 3 L LOF ha-1; E = ¾ RRCF + 6 L LOF ha-1; F = RRCF + 3 L LOF ha-1, and G = RRCF + 6 L LOF ha-1. The data were analyzed by ANOVA using SPSS 2.2 software, and result further tested using DMRT at 5% significance level. The addition 6 L LOF ha-1 with RRCF (G), seeds yield of maize reached 8.44 t.ha-1 it yield was higher than the treatment of 3 L LOF ha-1 with RRCF (F) which was 7.85 t.ha-1. The calculation of the RAE value showed that treatment G obtained the highest RAE value of 139.46%, while the second highest RAE value was obtained for treatment F of 119.73%.


Introduction
Corn is a strategic commodity for Indonesia which can be used as animal feed, staple food for most of the population, industrial raw materials, and energy (bioethanol) [1].Maize plant during its growing period to produce optimal yield and its necessary inorganic and organic fertilizers had to be added.Usuallly the nutrient element in soil not sufficient for its growth therefore the plant require balance fertilization according to avaibility of nutrient element in the soil and requirenment of the plant [2].The gift of inorganic fertilizers that are offset by organic fertilizers is highly recommended in agricultural business systems.
Organic fertilizer could decrease chemical fertilizer residue, added macro and micro nutrients in the soil, water infiltration, and increase Capation Exchange Capacity (CEC) [3].The application liquid organic fertilizer for maize plant during its growth and development period could decrease disease attack and improved soil degradation due to its content of microorganism.The liquid organic fertilizer content the delicate nutrient element, therefore leaf and stem of maize could absorb easily by spraying its liquid organic fertilizer in the leaf or stem [4].The application of fertilizer into the plants through leaves was successfully carried out on corn plants [5,6].The function of fluid fertilizer is the same as that of solid fertilizers, but nitrogen from fluid fertilizer is easier to obtain and the nitrification process takes place more quickly [7].Liquid organic fertilizer also contains micro nutrients, not just macro, although in small amounts it will greatly support plant growth.The advantage of liquid organic fertilizer is that the nutrients contained in it are more easily absorbed by plants he compounds inside are already decomposed.Liquid fertilizer can work faster than solid fertilizer, because the fertilizer has dissolved into the liquid so that plants will quickly absorb it in greater quantities [8].Liquid organic fertilizer also has a binder, so that the fertilizer solution applied to the soil surface can be directly absorbed by the plants.The use of organic fertilizers in the long term can increase land productivity and prevent land degradation so that soil conservation becomes better [9].Organic N combined with chemical N was shown to significantly increase N use efficiency, and it was easily implemented in paddy.Combining inorganic and fluid fertilizers enhances nutrient uptake for growth and rice production [10].
The study aim to determine the effectiveness of liquid organic fertilizer on maize to increase yield in dry land.

Materials and methods
The research conducted at dry land of Keling Village, Kepung Subdistrict, Kediri Regency, East Java Province, Indonesia, Dry Season (DS) I, since May untill October 2018.

Research methods
Field experiments were arranged in a Randomized Block Design (RBD) with 7 treatments and 4 replications (Table 1).Observation data on the growth and yield of maize were statistically analyzed using SPSS 22.The data obtained were analysed using the F test at a significant level of 5%.In the treatment that showed a noticeable difference, it was continued with a real difference test using the DMRT at 5% level.The level of effectiveness of the LOF treatment on yields used the RAE value to test each fertilization treatment against standard fertilizer.RAE is the ratio between the yield increment due to fertilizer application and the increase of yield with the use of standard fertilizer multiplied by 100 [12].The formula for RAE as follows : The level of profit and efficiency of farming is a measure of the feasibility of managed farming technology, calculated using R/C-ratio.Analysis tool for R/C-ratio [13] with equation as follows: R/C ratio = TR/TVC (Where : R/C ratio = Revenue cost ratio, TR = Total revenue, TVC = Total variable costs.

Soil chemical status
At the beginning of the test, soil samples were taken to determine the soil fertility status.The research sites was classified as inceptisol soil and had a dusty clay texture with low organic C content (1.00%), low N-total (0.15%), moderate P2O5 (18.86 mg.kg -1 ), moderate K (0.30 me.100 g -1 ) and moderate CEC (24.12 cmol c kg -1 ) [14], so it was necessary to add organic matter by applying organic fertilizer.Organic matter has a role in soil properties and plant growth including to improve soil structure, sources of macro and micro nutrients, increase the ability of the soil to retain water, and increase the ability to hold nutrients (CEC become high) [15].

Maize growth and yield
3.2.1.Growth component.The results analysis of variance showed that the treatment had a significant effect on the variables of maize growth, and leaf area per plant (Table 2).The combination effect of the treatment G = RRCF + 6 L LOF ha -1 had an better effect than the other treatment and it is indicated that using chemical fertilizer only not sufficient so needed liquid organic fertilizer.The treatment G = RRCF + 6 L LOF ha -1 showed the highest height plant at 63 DAP as 225.10 cm and increase by 45.65% compared to treatment A.
The plant height of sweet corn with Liquid Organic Fertilizer "NASA" administration concentration forms positive quadratic relationship with the Ŷ equation = 171.1 + 19.18x -4.166x 2 and the value of r = 0.939.The plant height sweet corn will increase up to the maximum concentration limit.Increased concentration over concentration Liquid Organic Fertilizer "NASA" maximum award will be causing a decline.As for concentration Liquid Organic Fertilizer "NASA" maximum award was 2.26 ml 0.5 -1 of water [16].
The treatment G = RRCF + 6 L LOF ha -1 on the number of leaves per plant showed a better effect than treatment D, E, F, and was significantly different from than treatment A, B, and C. The highest the number of leaves per plant was 2.28 cm and 14.25 blade combined with RRCF + 6 L LOF ha -1 .
The treatment G = RRCF + 6 L LOF ha -1 tended to show better stem diameter than control (A), only chemical fertilizer (B) and only liquid organic fertilizer treatment (C).Application of a combination of LOF and chemical fertilizer (D, E, F, G) on stem diameter and leaf area showed a better effect and significantly different from control (A).The highest stem diameter and leaf area per plant were 2.28 cm and 5.686 cm 2 obtained the treatment 6 L LOF ha -1 + 300 kg Urea ha -1 + 400 kg NPK 15-15-15 ha -1 (G).
There is a significant effect leaf area on the yield of seeds yield of maize.Leaf is the place where the plant changes the output of light interception and energy into seeds and the harvest yield, so that leaves play important roles for the plant growth.When the leaves grow perfectly, the possibility will be directly proportional to the harvest yields [17,18].
The stem of the corn plant is cylindrical and round not perforated but solid and filled with vascular bundles so that it gets bigger strengthening the stem.Corn stalks segmented and at the base of the stem segmented quite short with a number of about 8-20 segments.Corn stalks can grow to about 3-4 cm in diameter [19].NPK fertilizer in combination with LOF fertilization has an effect on the number of corn leaves.Fertilizer 100% NPK and 75% NPK combined with LOF did not significantly increase the number of sweet corn leaves compared to the control from 2 WAP until harvest.At the age of 2 WAP the number of sweet corn leaves ranged from 5-6 leaves and at the age of 8 WAP increased to 14-15 leaves [20].

Yield component.
Analysis of variance showed that treatment using the combination of liquid organic and chemical fertilizer increase the componen yield of maize (Table 3).Treatment of RRCF + 6 L LOF ha -1 (G), tend to give the higher in cob length, number of rows per cob, weight per cob, and seeds yield of maize although statistically not different from treatment of RRCF + 3 L LOF ha -1 (F).Treatment of RRCF + + 6 L LOF ha -1 (G), tend to give the higher in cob diameter, although statistically not different from combination treatment other (D, E, F).Treatment of RRCF + 6 L LOF ha -1 (G), tend to give the higher in weight of 100 seeds, although statistically not different from the recommended dose of chemical fertilizer treatment (B) and combination treatment other (D, E, F).Table 3 showed that F and G treatment gave the highest yield component consistently than the other treatments and not different statistically.The highest yield as maize yield was yielded by F and G treatment 7.85 and 8.44 t.ha -1 respectively.
The formation of the cob and the filling of the seeds is an illustration of the function of photosynthesis which is translocated for the development of reproductive organs.Sufficient photosynthate translocation to the reproductive organs causes cob formation and seed filling to go well, the seeds formed are pithy, and larger in size [21].Liquid organic fertilizers have some benefits, for example, in supporting and increasing the formation of chlorophyll that will improve photosynthetic ability of the plant and nitrogen absorption from the air, increasing the vigor so that the plant will grow sturdy and strong, increasing the plant resistant to drought [22].

Relative agronomic effectiveness (RAE)
The RAE was used to to assess the effectiveness of fertilization, against recommended standard fertilizers i.e.B treatment (300 kg Urea ha -1 + 400 kg NPK 15-15-15 ha -1 ) which be valued 100% (Table 4).The liquid organic fertilizer treatment was less effective than the standard as indicated by the RAE value of less than 100, namely the C, D, and E respectively 65.89%, 95.31%, and 84.63%.The highest effectiveness of 139.46% was achieved by adding 6 L LOF ha -1 with standard dose (G).Decreasing the dose of liquid organic fertilizer by 3 l ha -1 with standard dose (F) reduced its effectiveness to 119.73% but it was still higher than the standard dose (B).

Profit rate and efficient farming jn Kediri Regency, 2018
The highest net profite increase was observed in the treatment RRCF + 6 L LOF ha -1 (G) followed by RRCF + 3 L LOF ha -1 (F).Indicators of the feasibility of the managed farming are the level of profit and efficiency of the farming business (Table 5).Input output analysis to determine the efficient fertilization dose assuming that the production costs calculated are the costs of providing production facilities, the costs of fertilization, harvesting costs, and the maintenance costs.The farming business analysis in this research was calculated using R/C ratio) [13].
The farming analysis showed that the use of 1 RRCF + 6 L LOF ha -1 (G) obtained R/C-ratio of 2.81, and a profit of IDR 23,910,000, followed by RRCF + 3 L LOF ha -1 (F) obtained an R/C-ratio of 2.72 and a profit of IDR 21,820,000.In the fertilization treatment of RRCF (recommended dose) (B) obtained an R/C-ratio of 2.56 and with a profit of IDR 19,460,000.
The use of LOF was economically profitable due to both R/C ratio and B/C ratio are higher than 1 (> 1), means that the farming was running efficiently [14].Based on this, in terms of farming, the technology of applying liquid organic fertilizer was feasible to be developed.

Conclusion
The addition 6 L LOF ha -1 with RRCF (300 kg Urea ha -1 + 400 kg NPK 15-15-15 ha -1 ) (G), showed the highest of growth components and the yield components in comparison with other fertilizer treatment.The calculation of the RAE value showed that treatment G = RRCF + 6 L LOF ha -1 obtained the highest RAE value of 139.46%, while the second highest RAE value was obtained for treatment F = RRCF + 3 L LOF ha -1 of 119.73%.Based on the analysis results of the farming business, the highest total profit by G treatment reached IDR 23,910,000, while treatment F obtained the second largest total profit of IDR 21,820,000.

Table 2 .
The growth components of maize and leaf area per plant with liquid organic and chemical fertilizer treatment in dry land, DS I, 2018, Kepung Subdistrict, Kediri Regency Numbers followed by the same letter in the same column are not significantly different in the Duncan 5% test

Table 3 .
The yield components of maize with liquid organic and chemical fertilizer treatment in dry land, DS I, 2018, Kepung Subdistrict, Kediri Regency Numbers followed by the same letter in the same column are not significantly different in the Duncan 5% test

Table 4 .
RAE value of LOF treatments on Bisi 18 variety

Table 5 .
Financial analysis of maize farming in the dry land, DS I, 2018, Kepung Subdistrict, Kediri Regency