Relative performance of neem ( Azadirachta indica ) coated urea

Relative performance of neem ( Azadirachta indica ) coated urea vis-a-visordinary urea applied to rice and wheat in Kapurthala district of Punjab, IndiaRajan Bhatt*, Manoj Sharma and Gurpreet Kaur

Krishi Vigyan Kendra, Kapurthala*

rajanbhatt79@rediffmail.com

Abstract

:

Field experiments conducted over two seasons (2006–2008) in a sandy loam soil evaluatedtwo N sources (coated and uncoated urea) at two levels, namely 80% and 100% of the recommendedlevel of 120 kg N ha−1 , applied in three equal doses: at transplanting, 21 days after transplanting, and42 days after transplanting (DAT) of paddy whereas half N applied at sowing and half broadcasted atfirst irrigation in wheat. Both the forms increased grain yield of rice significantly, with higher yields atthe higher level of N, and the coated form at the recommended level led to the maximum yield,particularly in rice. The coated form also led to marked increase in N uptake.

Keywords:

 Neem coated urea; Rice ; Wheat; Ordinary urea; Grains Urea is a major nitrogenous fertilizer. Of the total quantity of urea applied to crops, 50%–70%is estimated to be lost, in various forms, thereby reducing the availability of nitrogen to crops. Therecovery efficiency of N fertilizer in rice ranges between 30% and 40% (Bijay-Singh and Yadvinder-Singh 2003); improving the efficiency is therefore vital not only to achieving and sustaining high cropyields but also to safeguarding the environment, considering the potentially harmful effects of theleached N. Slow-release N-fertilizer is one of the means to achieve this end. In rice, sulphur-coatedurea outperformed ordinary urea in almost all types of soils (Meelu et al. 1983; Bijay-Singh and Katyal1987). Blending urea with neem cake has been a traditional practice in India, and neem products,when applied along with urea, have been shown to enhance nitrogen use efficiency (NUE) in rice(Agarwal et al. 1980; Singh and Singh 1986). Oil derived from neem seed contains melicians(generally known as neem bitters), of which epinimbin, deacetyl, salanin, and azadirachtin show dose-dependent inhibition of nitrification (Devakumar and Goswami 1992). Although it had been establishedlong ago that neem products, when applied along with urea, can enhance NUE in crops (Singh andSingh 1986), the practice did not find large-scale application because a process to coat urea withneem products on a large scale was not available. The Indian Agricultural Research Instituteperfected the technique of coating urea using neem oil emulsion at 0.5–1.0 kg neem oil per tonne of urea (Suri et al. 2004). The technique is used at the factory level, and the product meets thespecifications stipulated in the fertilizer control order. The use of neem-coated urea (NCU), producedby spraying neem (

 Azadirachta indica

L. Juss.) oil emulsion on prilled urea at the final stage of production, can result in high NUE in rice because neem oil can inhibit nitrification. Coating of ureaprills with neem oil in this way is very economical as it costs only about INR 100, or about $2, per tonne of urea. The National Fertilizer Ltd adopted this technology at its plant in Panipat, Haryana, inIndia and neem-coated urea is now a commercial product. The oil forms a fine coating and protects

 

the loss of nitrogen due to denitrification, ensuring regulated and continuous availability of nitrogenover a long period, as required by crops. The present investigations were undertaken to evaluate therelative performance of coated and uncoated urea in the field for rice and wheat in different villages inKapurthala district of the north Indian state of Punjab. 

MATERIALS AND METHODS

Site characteristics:Field experiments were conducted at 18 sites for 2006-2008 in both the crops viz. wheat and paddy.Kapurthala (A formerly princely state) is one of the smallest districts of Punjab and is located at 31

o36’North and 75o

37’ East at an attitude of 221 meters. The district is divided into two non–continuousparts viz. Phagwara block in one part and the remaining four blocks in the other part. The agro-climatic conditions of the district Kapurthala coincide with the Central Punjab with smooth-plaintopography. The climate of the experimental site is sub-tropical, semi-arid with an annual rainfall of 733 mm, of which about 80% is received during June to September when wetland transplanted rice isgrown.Treatments:NCU and ordinary urea were tested at two N levels i.e. 80 and 100% of the recommended level of 120kg N ha

-1for the region. The performance of NCU vis-a`-vis ordinary urea was also studied basal doseconsisting of 26 kg P, 30 kg K ha-1 and 10 kg Zn ha-1 was applied to all the plots at the time of transplanting of Paddy. The entire amount of P, K and Zn was incorporated into the top soil with thelast run of cultivator, while N was top dressed in three equal splits viz. at the time of transplanting and3 and 6 weeks after transplanting. Wheat (cv PBW 343) was seeded in 0.20 m apart rows at 100 kgha-1in November. The crop received 120 kg N ha-1

(through urea), 63 kg P ha-1and 30 kg K ha-1. Half of N was applied at sowing while rest was broadcast prior to common irrigation 4 weeks after sowing.The crop was harvested in the middle of April each year. However, other crop management frompreparation to harvesting was identical in all treatments and were based on recommendations fromPunjab Agricultural University, Ludhiana (Anonymous 2005). As far as rice is concerned, fields werepuddled and levelled for transplanting irrespective of the variety. Four-week-old seedlings of rice weretransplanted however, for wheat we also follow standard procedure for field preparation. At maturity,grain yields were recorded. After estimating moisture content, the grain yield was reported at 14%moisture content in both crops viz. Wheat and Paddy. In the present study we tried to check-out theresponse of two different levels of N-fertilisers viz. 80% and 100% through ordinary and Neem coatedurea in wheat and paddy. In these experiments, we selected a plot of 2 acres and then divide this intothe four equal plots of 4 Kanals. On two plots, we applied NCU @ 80% and 100% of therecommended level of 120 kg N ha –1

and on other two we applied normal urea with the samespecifications. Experiments were conducted irrespective of the cultivars. The crop was harvested byhand at ground level at maturity in the month October-November and April and grain yields wererecorded from a 100 m2 area in the centre of each plot. The water table is deep and soils are finetextured. Farmers were selected randomly by the scientific staff and preference was given to educated and willing farmers who could understand the philosophy of insect control through neem oilcoated urea. The experiments were conducted with the cooperation and help of farmers.

In thisregard, to check the response of Neem coated urea on the ordinary urea, we carried out this study atdifferent villages of Kapurthala district of Punjab, India. We selected the plots and then divide theminto the four sub-plots.Treatments comprised of T

1: Neem coated urea (80%)T

2: Normal urea (80%)T

3; Neem coated urea (100%)T

4: Normal urea (100%) 

RESULTS AND DISCUSSION

Application of N through NCU or ordinary urea up to 100 % significantly increased grain yield of riceand wheat as compared to 80% application. When applied in three equal split doses at 0, 21 and 42DAT, the NCU did not outperform. In 2006/07, wheat yield with NCU was 0.23% higher than that withordinary urea at the lower dose; at the higher dose, the corresponding gain was 0.21% (Table 1). In2007/08, at the lower dose of N, use of NCU resulted in the grain yield of wheat being 0.52% greater than that when ordinary urea was used; at the higher dose, the yield was greater only by 0.1% (Table1). These results suggest that the impact of nitrification-inhibiting properties of NCU is more visible inthe coarse-textured soils of Kapurthala, Punjab. Rice responded better to NCU than wheat did in2007, at the lower dose of N, grain yield was 1.3% higher in plots supplied with NCU than in thosesupplied with ordinary urea; at the higher dose, the corresponding figure was 1.4% (Table 2). In 2008,the corresponding increases were 0.86% at the lower dose and 1.54% at the higher dose (Table 2).From the above it is clearly stated that the effect of neem coated urea is more prominent in paddy (Fig2) as compared to that of the wheat (Fig 1) and it may be because of the nitrification inhibitionproperties of Neem coated urea.The recommended dose applied in the form of NCU led to the highest yields, the treatmentbeing significantly better for wheat (4598 kg ha –1and 4364 kg ha –1respectively in 2007/08 and2008/09 than 80% of the recommended dose (Fig 3), whether given in the form of ordinary urea (4185kg ha –1and 4178 kg ha –1respectively) or in the form of NCU ( 4195 kg ha –1and 4195 kg ha –1respectively) although at the higher dose the two forms were statistically on par (4592 kg ha –1and4358 kg ha –1respectively) (Table 3). The pattern with paddy yield was identical, with 100% N appliedas NCU performing significantly better (7305 kg ha –1and 6558 kg ha –1in 2007 and 2008 respectively)than 80% N applied either as ordinary urea (6145 kg ha –1and 5754 kg ha –1respectively) or as NCU(6230 kg ha –1and 5898 kg ha –1respectively) but being statistically on par with the treatment involving100% N given as ordinary urea (7225 kg ha –1and 6456 kg ha –1respectively) (Fig 4). The beneficialeffects of various neem products, when used in combination with ordinary urea, are well establishedand take the form of smaller N losses and higher yield. Singh and Singh (1986) observed a significantreduction in nitrogen being leached as NO3-N when urea was blended with neem cake. Blending  neem seed cake with urea reduced volatilization of ammonia by 31.4% (Reddy and Mishra 1983). Thecoated form produced 5.6% higher grain yield than that produced by ordinary urea when applied inthree equal split doses. These results suggest that the positive impact of the nitrification-inhibitingproperties of NCU is more visible in coarse-textured soils of Kapurthala district of Punjab. Since neeminhibits nitrification, the main effect of NCU in improving NUE in rice is probably due to the reduction inthe amount of nitrogen being lost by leaching in the form of NO3-N. However, as reported byMikkelsen and De Datta (1979) and Vlek and Craswell (1979) for coarse-textured soils, whenconditions are unfavourable for nitrification, N volatilization is greater—and NCU may well have beeninstrumental in checking the loss of N in this form. This study shows that NCU is superior to ordinaryurea in wetland rice. Commercial production of NCU requires large-scale availability of neem oil,which can be ensured only by encouraging large-scale plantation of neem trees. Growing of neemtrees will also lead to increased carbon sequestration, thereby helping to mitigate the adverse effectsof climate change.It may be concluded from the above discussion that application of nitrogen in the form of neem-coated urea increased grain yield in rice significantly compared to that in wheat. Applying NCUat the recommended rate of 120 kg N/ha produced higher grain yield in rice compared to that obtainedwith ordinary urea. It may be assumed that the superiority of NCU over ordinary urea in theKapurthala district of Punjab was accompanied by a marked increase in N uptake and nitrogen useefficiency

.

ACKNOWLEDGEMENT

Authors highly acknowledge the co-operation received by the farmers of Kapurthala district of Punjab for successfully conduction of these trials on to their fields from 2006 -- 2010. The timely helpreceived by Dr. H.S. Thind and Dr. Sanjay Arora is also highly acknowledged.

REFERENCES

Agarwal S.R., Shankar, H. and Agarwal, M.M (1980) Effect of slow release nitrogen and nitrificationinhibitors on rice-wheat sequence.

Indian J Agron

35:337–340.Anonymous (2005) Rice. In: Mahindra K (ed) Package of practices for crops of Punjab–Kharif crops,vol 22 (No. 1). Punjab Agricultural University, Ludhiana, pp 1–18Bijay-Singh and Katyal JC (1987) Relative efficacy of some new urea-based nitrogen fertilizers for growing wetland rice on a permeable alluvial soil.

J Agril Sci Camb

109:27–31Bijay-Singh and Yadvinder-Singh (2003) Efficient nitrogen management in rice-wheat system in theIndo-Gangetic plains. In: Yadvinder-Singh, Bijay-Singh, Nayyar VK, Jagmohan-Singh (eds)Nutrient management for sustainable rice-wheat cropping system. National AgriculturalTechnology Project, Indian Council of Agricultural Research, New Delhi and PunjabAgricultural University, Ludhiana, pp 99–114Bijay-Singh and Yadvinder-Singh (2004) Balanced fertilization for environmental quality–Punjabexperience.

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